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PHYSIOLOGY 103 Classes 1-5 Summary Chemical Level - atoms, molecules, organelles Cellular Level – muscle cells, nerve cells, adipose cells, epithelial cells Tissue Level - epithelium, muscle, connective, nervous Organ Level - heart, lungs, stomach Organ System – cardiovascular, digestive, respiratory Organism Level Necessary Functions for Life 1. Maintain boundaries 2. Movement 3. Responsiveness/Irritability 4. Digestion 5. Metabolism 6. Excretion 7. Reproduction 8. Growth Survival Needs 1. Nutrients - carbohydrates, proteins, fats, minerals and vitamins 2. Oxygen 3. Water 4. Normal Body Temperature 5. Atmospheric Pressure Homeostasis homeostasis = the body’s ability to maintain its relatively stable internal conditions even though the outside world changes constantly Negative Feedback Positive Feedback Basic Chemistry – atoms, ionic and covalent bonds explains how the body is made of C, H, O, Na, Cl, Basic Biochemistry – organic and inorganic makeup of the body basic understanding of what the body is made of Inorganic compounds A. Water Functions of water: 1. Formation of Solutions 2. Reactivity 3. Temperature Regulation 4. Cushioning 5. Lubrication B. Salts Functions of salts: ionic compounds that carry an electric current in water…..electrolytes…when forming their ionic bond, they became charged, when they split in water that negative or positive ion exerts a pull on other positive or negative ions which creates movement of ions, creating an electric current…nerve impulse transmission and muscle contraction depend on the electrolyte properties C. Acids and Bases Functions of acids and bases: chemicals used for various processes in the body…ex HCl…acid needed to digest food H other acids and bases are needed to keep the body under control in disease states..body can become acidic or basic and we need to correct it Organic Compounds A. Carbohydrates – contain carbon, hydrogen and oxygen Functions of CHO: (Monosaccharides, Disaccharides, Polysaccharides) great source of energy and storage B. Lipids - contain carbon, hydrogen and oxygen, some have phosphorous Functions of lipids: (triglycerides, phospholipids,steroids) the most efficient and compact form of stored energy (triglycerides) insulate deeper tissues from heat loss (triglycerides) protect deep tissues from mechanical trauma (triglycerides) important in building cell membranes (phospholipids) found in cell membranes, in vitamin D, hormones, bile salts(cholesterol/steroids) C. Proteins - contain carbon, oxygen, hydrogen and nitrogen Functions of proteins: (amino acids) basic structural material of the body mechanical support, tensile strength (fibrous) ex. collagen, keratin movement - create muscle contraction (fibrous) ex. actin and myosin catalysts , transport, regulation of pH (globular) regulation of metabolism, hormones, body defense (globular) D. Nucleic Acids – contain carbon, hydrogen, nitrogen, oxygen, phosphate Functions of nucleic acids: (DNA, RNA) genetic code (DNA) provides instructions for building proteins (DNA) protein synthesis (RNA) E. ATP – contains ribose sugar, 3 phosphate groups, adenine (basically an adenine nucleotide) Functions of ATP: useable energy to make and breakdown molecules transport substances across membranes muscle contractions PHYSIOLOGY 103 Class 1 - Introduction Summary What are Anatomy and Physiology and How are They Related? Anatomy vs. physiology anatomy = structure and organization of body parts physiology = functioning of body parts Levels of Organization if the Human Body Chemical Level atoms…..oxygen, carbon, hydrogen etc molecules……water, bicarbonate, carbon dioxide, protein organelles……mitochondria, ribosomes Cellular Level cells…the smallest units of living things, all body parts are made of cells cells combine to form tissues Tissue Level tissues are groups of similar cells with a common function 4 basic types of tissues – epithelium, muscle, connective, nervous Organ Level organ = structure composed of at least 2 tissue types that perform a specific function Organ System organ systems are made up of organs that work together to accomplish a common purpose Organism Level highest level of organization = organism = human being Necessary Functions for Life 1. Maintain boundaries ensures internal environment remains distinct from external environment encloses contents while restricting entry of damaging or unnecessary substances 2. Movement within our environment , within our body, within our cells 3. Responsiveness/Irritability ability to sense changes in the environment and respond to them nerve cells communicate rapidly and are highly irritable…sensitive to change and able to send an electrical message in response 4. Digestion breakdown of ingested food to simple molecules to be absorbed into blood 5. Metabolism all chemical reactions that occur in the body 6. Excretion removing waste from the body 7. Reproduction cellular level – original cell divides producing 2 identical cells – used for growth and repair organism level – reproductive system 8. Growth increase in size of a body part or the organism accomplished by increasing the number of cells or size of cells Survival Needs 1. Nutrients chemical substances used for energy and cell building carbohydrates, proteins, fats, minerals and vitamins 2. Oxygen needed for the chemical reactions that release energy from food 3. Water environment for chemical reactions, fluid base for secretions and excretions 4. Normal Body Temperature must be maintained for chemical reactions to continue normally 5. Atmospheric Pressure breathing and gas exchange in the lungs depends on appropriate atmospheric pressure Homeostasis homeostasis = the body’s ability to maintain its relatively stable internal conditions even though the outside world changes constantly Regulating Homeostasis nervous system and endocrine system are the major systems involved….electrical impulses and hormones allow communication receptor = a sensor that monitors the environment stimuli = change in the environment input = information from stimuli afferent pathway = carries information towards control centre control centre = integrative centre output = information being carried away from control centre efferent pathway = carries information away from control centre effector = performs the appropriate response Negative Feedback if the body starts to deviate from optimal….response occurs to reduce the deviation….return to original state causes a response opposite to what was occurring…..negative feedback Positive Feedback response enhances the original stimulus so the activity is accelerated positive….means the response occurs in the same direction as the original change/deviation/disturbance causing further deviation from the original state Homeostasis and Stress stress stimulates the hypothalamus hypothalamus is the major homeostatic control centre of the body stimulates many glands to release hormones to attempt to return to homeostasis Cortisol is one hormone that is released…acts on many tissues, stress adaptation hormone, steroid hormone mobilizes energy reserves enhances effects of epinephrine (Adrenaline) on vasoconstriction cortisol will suppress inflammation excess may cause decreased immunity, ulcers, depression of bone/cartilage formation Physiology 103 Class 2 – Basic Chemistry Summary Atom smallest stable unit of matter (matter is “stuff”) consists of subatomic particles…protons, neutrons, electrons protons have a +ve charge, located in nucleus neutrons are neutral, located in nucleus electrons have a –ve charge, orbit the nucleus all atoms are electrically neutral…# protons is balanced by # electrons atoms of different elements are composed of diff numbers of those which makes them unique and different from each other Atomic Number atomic number = # of protons (indirectly tells us the #of electrons)…#electrons determines chemical behavior different atoms have a different atomic number The Elements elements are made of atoms with the same number of protons ex. oxygen, carbon, gold, silver, copper, iron 112 elements carbon, oxygen, hydrogen, nitrogen make up 96% of body weight most atoms combine with other atoms…form a chemical bond to form a molecule ex. 2 hydrogen atoms = a hydrogen molecule H2 2 or more different kinds of atoms combine = a molecule of a compound ex. H2O, CH4 methane Chemical Bonds when atoms combine, they form chemical bonds….they are not a physical structure but an energy relationship between the electrons of the reacting atoms electrons around the nucleus occupy regions called electron shells atoms can have up to 7 shells, number of shells depends on number of electrons electrons far from the nucleus have less attraction to their nucleus the farthest are most likely to interact with other atoms…they are the least tightly held by their own nucleus each electron shell can hold a specific number of electrons shell 1 – 2 electrons shell 2 – 8 shell 3 – 18 each shell fills before the next outermost shell interacts in bonding with other atoms inner electrons are held tighter…attracted to their nucleus if outer layer is full…..atom is stable….inert…unreactive…noble gases…..helium, neon atoms with fewer than 8 electrons in their outer shell will gain, lose or share electrons with other atoms to become more stable…not stable with less than 8 ex. oxygen… has 6 electrons in outer shell….incomplete ex. hydrogen…has one electron in its shell…..incomplete ex. sodium…has 11 electrons……2, 8, and then 1 in outer shell…incomplete atoms will combine with other atoms so that they end up having 8 electrons in the outer shell Ionic Bonds electrons from atoms can be transferred from one atom to another……..they want to be both structurally stable and electrically stable…….in natural state they are electrically stable but they are structurally unstable …..with vacancies in their outer shell when an atom loses or gains an electron, its balance of + and –ve is lost and it is electrically unstable and is called an ion If an atom gains an electron…..it has gained one more –ve bit….so it is called an ANION and it is now negatively charged ex. chloride…7 electrons in outer shell...wants to fill its outer shell…so it will find an atom with one electron in its outer shell and steal that one…..when it accepts that one it now is stable structurally but is electrically negative with one extra electron The atom that gave up the electron, gave up one bit of negativity so it is now positive…CATION (positive relative to its resting state) ex. sodium…one electron in its outer shell……will give up that one (and now the outermost shell/valence shell has 8 in it and it is stable) to chloride so sodium standing alone would be na+ and the chloride alone would be cl because opposite charges attract….. the +ve sodium and the –ve chloride tend to stay close together and form an IONIC bond Covalent Bonds Some bonds may be formed by sharing their outer ring so they can fill their outer rings and be stable…they don’t transfer the electrons that shared orbital becomes a single orbital common to both atoms…COVALENT BOND…strong bonds common examples…H2 O2 CO2 H2O CH4 Single vs. Double covalent bonds in the above examples: H2…each H needed to share one electron….single bond O2…each O2 needed to share 2 electrons …. double bond (much more efficient that sharing one with 2 separate ones) CH4…C needed 4 and each H needed one so 4 single bonds CO2…C needed 4 and each O needed 2 so 2 double bonds H2O…O needed 2 and each H needed one so…single bond Phys 103 Class 3 - Biochemistry Summary Biochemistry the chemicals and reactions of living matter organic = contain carbon, are covalently bonded, protein, carbs, fats inorganic = all other chemicals in the body…water, salts, acids, bases Inorganic compounds A. Water B. Salts C. Acids and Bases A. Water Functions of water 1. Formation of Solutions water is the solvent for many chemicals (solutes) to react nutrients, respiratory gases and metabolic wastes dissolve in blood to be transported through the body 2. Reactivity water is a reactant in many chemical reactions ex. foods during digestion break down into their building blocks by adding water molecule to each bond to be broken -- hydrolysis ex. large CHO or PRO molecules are synthesized from smaller molecules, water is removed from every bond formed – dehydration hydrolysis - water molecule causes other molecules to split. ex. long CHO molecule….the water molecule splits and the OH joins the part released from the chain and the H fills the space that was vacated on the end of the chain dehydration synthesis - 2 molecules join and H2O is released ex. making glucose in the body….gluconeogenesis….as another molecule is added to the chain, an H comes off the existing chain and an OH comes off the part to be added on and that piece is added and the H2O is made and released 3. Temperature Regulation water absorbs and releases large amounts of heat before changing temperature noticeably prevents sudden changes in body temp caused by external factors or changing internal factors redistributes heat among body tissues via blood to maintain temperature homeostasis when large amounts of heat are absorbed the hydrogen bonds are broken that hold H2O together, allowing evaporation…sweat to occur as water evaporates from our skin large amounts of heat are removed from the body providing a cooling mechanism 4. Cushioning forms a resilient cushion around certain body organs…protecting them from physical trauma ex. CSF around brain 5. Lubrication lubricating molecules such as mucus are water based B. Salts salt = ionic compounds containing cations other that H+ and anions other than the OHex. NaCl, KCl, CaCO3 when dissolved in water the dissociate into their component ions this occurs easily because the ions are already formed, the water just needs to overcome the attraction between the ions carry an electric current in water…..electrolytes…when forming their ionic bond, they became charged, when they split in water that neg or pos ion exerts a pull on other pos or neg ions which creates movement of ions, creating an electric current nerve impulse transmission and muscle contraction depend on the electrolyte properties C. Acids and Bases Acids - substance that releases H+ when they dissolve in water (proton donor) Bases - substance that releases OH- in water, and take up H+ ions in water (proton acceptors) pH - Acid Base Concentration more hydrogen = more acidic = lower pH more OH = more basic/alkaline (means there is less H+) = higher pH scale from 0-14 each increase in 1 number is a 10 fold increase in concentration at pH 7 amount of H = amount of OH as H increases there is relatively less OH ex. red food colouring = acid, blue food colouring = base neutral = purple add red….more acidic….more H now…more H than OH add blue…more basic….more OH now…..more OH than H as you increase the amount of hydrogen in solution…..the ph goes from 7 to 6, 5, 4, … as you increase the amount of OH in solution ….ph goes from 7 to 8, 9,10... going from 7 to 6 means you added 10 times the existing amount of H in solution going from 7 to 8 means you removed 10 times the existing amount of H in solution, but how do you remove H? add OH to bind to it, so going from 7 to 8 you increased the amount of OH by 10 times again….the blue and red…….at 7 it is purple at 4 you added more red…more H….more acidic…..now more red than blue, more H than OH… at 8 you added more blue…more OH…more basic… or took away some red so you have less red now…less H than OH….. and more blue….more OH H and OH are opposites...if you think from neutral….as you increase the H, the relative amount of OH in relation to the whole solution is now decreasing, if you do not add or subtract any OH the number of particles is staying the same but it is now taking up a smaller amount of that total solution pH above 7 is called a base or alkaline, pH below 7 is acidic as H increases, the relative amount of OH decreases, and as H decreases, the relative amount of OH increases as OH increases, the relative amount of H decreases, and as OH decreases, the relative amount of H increases Buffers lungs and kidneys work to regulate our ph by a chemical system of BUFFERS if pH of a solution gets too high…to basic…a buffer will release some of its H into the solution if pH of a solution gets too low….too acidic….a buffer will pick up some of that H and binds it to itself and carry it away so there is less H is that solution now weak acids and weak bases have the ability to lose or gain H and OH weak acid H2CO3 - carbonic acid weak base HCO3 - bicarbonate when pH rises (basic) due to low H in solution or high OH in solution…..the weak acid….H2CO3 will release H …that addition of H will decrease the pH, increase the acidity (when the H2CO3 lost the H it became HCO3, a weak safe base, and the H floats free or binds to OH to make H2O….bringing the pH from basic down towards neutral) when pH falls (acidic) due to high H in solution or low OH in solution…..the weak base…HCO3 will bind the H ….. that removed the H from solution and will increase the pH, decrease the acidity (when the HCO3 picked up the H it became H2CO3, a safe acid) H2CO3 weak acid ….releases H if not enuf H in blood (high pH, basic)…released H will add H to blood….decreases the pH, increase the acidity…….H2CO3 now becomes HCO3…weak base…ok in blood HCO3 weak base…binds H if there is too much in blood (low pH, acidic)……removing free H from blood……increases the pH, decreases the acidity….more basic……HCO3 now becomes H2CO3…weak acid….ok in blood ORGANIC COMPOUNDS Carbohydrates sugars and starches carbon, hydrogen and oxygen hydrogen and oxygen usually appear in a 2:1 ratio Monosaccharides one sugar, simple sugar, chain or ring of 3-7 carbons 1:2:1 ratio of carbon:hydrogen:oxygen ex, glucose C6H12O6 Disaccharides double sugar, 2 monosaccharides are joined sucrose-----glucose and fructose table sugar lactose------glucose and galactose milk maltose------glucose and glucose malt sugar must be digested to their smaller units to be absorbed into blood this is hydrolysis…adding water allows the bonds to break between each unit Polysaccharides long chains of simple sugars linked together insoluble, ideal storage molecules, ex. starch and glycogen Physiology 103 Class 4 - Lipids Summary Lipids insoluble in water dissolve in other lipids contain carbon, hydrogen and oxygen low amounts of oxygen some have phosphorous Types of lipids: triglycerides phospholipids steroids 1. Triglycerides (Neutral Fats) solid = fat liquid = oil come from food and we produce them from eating excess calories made of 1 glycerol and 3 fatty acids fatty acids – carbon and hydrogen chains with a COOH group on the end glycerol – modified simple sugar – 3 carbon molecule triglyceride is 3 fatty acids joined to a glycerol backbone they do not mix with water they are the most efficient and compact form of stored energy Functions of Triglycerides: found beneath the skin insulate deeper tissues from heat loss protect deep tissues from mechanical trauma Saturated and Unsaturated length of fatty acid and degree of H saturation determines how solid it is saturated = all single covalent bonds between carbon these are straight, packed closely together, form a solid at room temp unsaturated = one or more double bonds between carbons one double bond = monounsaturated more double bonds = polyunsaturated double bonds cause the chain to kink so they cant be packed close enough to be solid trans fats oils that have been solidified by adding H at double bond sites unhealthy omega 3 fatty acids healthy polyunsaturated fatty acids 2. Phospholipids modified triglycerides glycerol and 2 fatty acid chains (nonpolar tail) phosphorous group (polar head) – attracts other polar/charged molecules…water,ions this polar/nonpolar characteristic is important in building cell membranes Steroids 4 interlocking hydrocarbon rings fat soluble contain little oxygen Cholesterol eat in animal products…eggs, meat, cheese we produce some in our liver found in cell membranes, in vitamin D, hormones, bile salts Physiology 103 Class 5 – protein and nucleic acids Summary Proteins 10-30% of cell mass basic structural material of the body enzymes, hemoglobin, contractile proteins contain carbon, oxygen, hydrogen and nitrogen Amino Acids building blocks of proteins 20 have amine group and organic acid group NH2 and COOH amino acid is made of: an H atom, amino group,carboxylic acid group, variable group amino acids join to form peptides 2 makes a dipeptide, 3 makes a tripeptide 10 + makes a polypeptide, 50+ makes a protein usually proteins have 100 to 10000 + Structure of Proteins primary structure polypeptide chain of amino acids secondary structure alpha helix – coils beta pleated sheet - accordian tertiary structure - ball quaternary structure - complex protein Classified as Fibrous or Globular Fibrous – strandlike many have secondary structure, some are quaternary insoluble in water, very stable mechanical support, tensile strength aka structural proteins…..chief building materials of body Functions: support: collagen – in connective tissue, bones, tendons, ligaments keratin – structural protein of hair and nails elastin – for durability and flexibility - ligaments movement: actin and myosin – in muscles – create muscle contraction cell division intracellular transport Globular compact, spherical, at least tertiary structure water soluble, chemically active, role in all biological processes aka functional proteins Functions: catalysts – salivary amylase…starch breakdown transport – hemoglobin – oxygen, lipoproteins transport lipids regulation of pH – some plasma proteins act as buffers regulation of metabolism – hormones…growth hormone, insulin body defense – antibodies Nucleic Acids composed of C, H, N. O, P largest molecules in the body store and process information inside cells Structure of Nucleic Acids long chain of nucleotides - nitrogen, sugar (C, H, O) and phosphate DNA is made of the sugar deoxyribose (same as ribose but with an extra OH) RNA is made of the sugar ribose the nitrogen containing groups are called adenine, guanine, cytosine and thymine in DNA but uracil in RNA nucleotides join together …the sugar from one attaches to the phosphate of the next then that sugar joins the next phosphate and so on and the nitrogen group hangs off the sugar DNA is 2 chains of nucleotides that line up together and the nitrogen groups/bases across from each other forms a bond …..so that a ladder-like molecule is created the sugar and phosphate for the backbone and the bases form the rungs the whole molecule coils like a spiral staircase…now called a double helix when the bases pair up, A bonds with T and G bonds with C RNA is a single strand Role of DNA: genetic code DNA replicates itself before a cell divides, so that new cells have the same genetic blueprint in them DNA provides instructions for building every protein in the body…protein is the basic structural material of the body DNA has the instructions for protein production….directs growth and development, instructs RNA what proteins to make Role of RNA: takes orders from DNA and makes the appropriate protein ATP adenine nucleotide…ribose sugar, 3 phosphate groups (triphosphate) and adenine joined to it ATP is created by capturing energy released from breaking down glucose and storing it in the bonds between the phosphate groups ATP is then useable as a form of energy by body cells the bonds between the phosphate molecules are broken using enzymes which transfer the phosphate groups from ATP to other compounds, which “phosphorylates” molecules and “primes” them so they are ready to work when that P is taken off….ADP is left ATP is replenished when glucose is broken down and phosphates are transferred from various molecules in the process and ATP is recreated ATP used to make and breakdown molecules, transport substances across membranes, muscle contractions, etc. Class 6 – The Cell - Summary Cell Types shape reflects function cells generally have the same basic parts and some common functions Parts of a Cell 1. Plasma Membrane 2. Cytoplasm A. Cytosol B. Organelles – Membranous: a. endoplasmic reticulum, b. golgi apparatus, c. lysosomes d. peroxisomes, e. mitochondria Nonmembranous: a. cytoskeleton, b. ribosomes, c. centrosomes d. centrioles 3. Nucleus - Nuclear Membrane, Nucleolus 1. Plasma Membrane separates intracellular fluid and extracellular fluid outside the cell regulates movement of substances in and out of cell fluid mosaic model - bilayer of phospholipid molecules with protein, cholesterol and glycolipid molecules dispersed in it proteins: integral: transport channels for water soluble molecules or ions, carriers for various substances, receptors for hormones peripheral: support the membrane, some are enzymes, some help in cell division, some form the glycocalyx 2. Cytoplasm cytosol plus organelles A. cytosol – fluid in which the other things are suspended B. organelles - membranous a. Endoplasmic Reticulum extensive system of interconnected tubes and parallel membranes enclosing fluid filled cavities that coils and twists through the cytosol RER – ribosomes on outside – secretory proteins, integral proteins and phospholipids are made here and enter the ER SER – tubules with enzymes that catalyze reactions involved in:lipid metabolism, cholesterol synthesis, lipoprotein synthesis, steroid hormone synthesis, synthesis of fat detoxification of drugs, pesticides, carcinogens, breakdown of stored glycogen to form glucose b. Golgi Apparatus “traffic director” for cellular proteins - modifies, concentrates and packages proteins and lipids made at the RER transport vesicles bud off from RER, fuse with golgi proteins are modified – sugar groups trimmed or added, phosphate added the proteins are tagged for delivery to a specific address, sorted and packaged in vesicles that bud from the other side of the golgi….vesicles pinch off and and go to plasma membrane and release their contents via exocytosis and pinches off vesicles with lipids and membrane proteins bound for plasma membrane c. Lysosomes contain digestive enzymes, digest invading bacteria viruses and cell debris, degrade worn-out organelles metabolic functions - glycogen breakdown for release d. Peroxisomes powerful enzymes - oxidases - detoxify harmful substances – alcohol, formaldehyde, neutralize free radicals…highly reactive chemicals with unpaired electrons that can scramble the structure of biological molecules e. Mitochondria produce ATP, power plant of the cell intermediate products of food fuels…glucose…are broken down to water and CO2 here in various parts of the mitoch membranes energy is captured as metabolites are broken down and ATP is formed with high energy bonds B. organelles : Non Membranous a. Cytoskeleton cell skeleton microtubules, microfilaments, intermediate filaments o microtubules - determine cell shape and organelle distribution o microfilaments - cell motility or change cell shape o intermediate filaments - internal guy wires to resist pulling forces b. Ribosomes site of protein synthesis some are free, some are attached to RER free – make soluble proteins that function in the cytosol on RER – make proteins for cell membrane or for export from cell c. Centrosome microtubule organization centre, near nucleus d. Centrioles form microtubules needed for mitosis form the basis of cilia and flagella Cilia and Flagella Cilia - motile cellular extensions, moves substances across cell surface Flagella - longer projection that propels the cell 3. Nucleus control centre contains instructions for building body’s proteins Nuclear envelope double membrane barrier with fluid filled space has pores that allow stuff in and out contains nucleoplasm Nucleoli found in nucleus, site of assembly of ribosome subunits….large in growing cells and cells that make lots of protein contains chromatin/chromosomes…DNA plasma membrane – fragile membrane, outer boundary of cell protoplasm - all the fluid in a cell…cytoplasm and nucleoplasm cytoplasm – intracellular fluid that is packed with organelles cytosol - fluid in which the other things are suspended endoplasmic reticulum – protein synthesis (RER), lipid synthesis and metabolism (SER) golgi apparatus – modifies and packages proteins lysosomes – digestion of bacteria, viruses, worn out organelles etc. peroxisomes – detoxifies harmful substances mitochondria – ATP synthesis cytoskeleton – cell support, shape and movement ribosomes – protein synthesis centrosome – microtubule organization centrioles – form microtubule network for cell division nucleus – controls cells activities, transmits genetic information and instructions for protein synthesis Physiology 103 Class 7 Summary Fluids Intracellular Fluid 2/3 of body’s water…inside cells Extracellular Fluid 1/3 of body water …outside/surrounding the cells ECF is….blood plasma (btw blood cells) and interstitial fluid (btw other cells) carries nutrients, ions, wastes, maintains homeostasis Composition of Fluids ICF :high K, Mg, PO4, low Na, Cl, HCO3, some protein ECF:high Na, Cl, HCO3, low K, Mg, PO4, also O2, glucose, fatty acids, amino acids, CO2, waste Plasma Membrane Functions 1. control cellular contents membrane controls entry and exit of nutrients, ions etc…..to maintain homeostasis in cell 2. communication receptors on cell…ex. neurotransmitter receptors on muscle/nerve cells allow communication among cells 3. structural support structural proteins in cell give it shape, allow cells to connect physically Structure of the Plasma Membrane fluid bilayer of phospholipids, selectively permeable embedded proteins, CHO, cholesterol integral proteins: transmembrane - span the width functions: anchors structures to cytoskeleton, receptors, carriers, transport channels or pores peripheral proteins:attached to integral proteins or to lipids in membrane functions: support the membrane, enzymes, help in cell division, some form the glycocalyx…sugar coating/fingerprint of the cell carbohydrates: on outer surface, form the glycocalyx Permeability of substances through plasma membrane …allows nutrients in, keeps undesirable stuff out …keeps valuable proteins in, allows wastes out 1. Fat soluble substances: vitamin A, fatty acids, steroids…..pass easily though due to lipids in membrane 2. small uncharged molecules O2, CO2, H2O, urea…pass easily…..may slip between the tails 3. small charged particles and larger particles ions and larger molecules…proteins….do not pass pass only through special protein channels Transport Through Plasma Membrane 1. Active Processes – require energy 2. Passive Processes – no energy required 2 Main Passive Processes: Diffusion and Filtration Diffusion tendency of molecules to distribute evenly in an environment molecules move away from areas where there is higher concentration and move towards areas where there is lower concentrations ….molecules move along/down their concentration gradient diffusion will occur until there is no net movement……equilibrium has been reached between the 2 areas Rate of Diffusion 1. size of gradient - greater difference between the 2 areas = faster movement 2. size of molecule - smaller = faster movement 3. electrical charge - like charges repel, opposites attract 4. temperature - warmer = faster diffusion Types of Diffusion 1. Simple Diffusion non polar and fat soluble substances diffuse through lipid bilayer oxygen, CO2, fat soluble vitamins….ADEK O2 – concentration higher in blood than cells….so always diffusing into cells CO2 – concentration higher in cells…..so diffuses into blood 2. Facilitated Diffusion some molecules….glucose, other sugars, amino acids, ions bind to protein carrier in membrane and are taken across membrane or moves through a water-filled protein channels 3. Osmosis diffusion of water through a selectively permeable membrane osmosis occurs when water concentration differs on 2 sides of a membrane water will move from an area where there is low solute concentration to high solute concentration….to evenly dilute a solution example…..a container with a membrane that is permeable to water and sugar…….water will move for the area of lower concentration of sugar to higher concentration of sugar…..if sugar is allowed to move, it will move to reach equilibrium ex. impermeable to sugar…if that membrane is impermeable to sugar…water will move into the compartment with more sugar the particles pulled water towards them,………osmotic pull….osmotic pressure osmotic means concentration osmolarity means how many solute particles are in a solution…..so the more solutes = greater osmolarity = greater tendency to pull water towards it Tonicity ability of a solution to change the shape of a cell by altering internal water volume…this is done by solutes pulling or pushing water towards or away from them isotonic solution - solution with same concentration of the cell...no water movement hypertonic solution - solution has a higher concentration of solutes than the cell does…this pulls water out the cell into the solution…cell shrinks hypotonic solution - solution has lower concentration of solutes/more dilute/more water than the cell…water rushes into the cell…cell bursts Filtration water and solutes forced through a membrane by pressure Class 8 Summary Active Transport, Membrane Potential Active Processes • requires energy…ATP…to move substances across a membrane • substances are unable to pass through the membrane passively…substances are too large, or incapable of dissolving in the lipid layer, or unable to move down their concentration gradient 2 types of active transport: active transport – movement against chemical gradients primary secondary vesicular transport – movement of large particles into or out of cell Active Transport • carrier proteins combine specifically and reversibly with a substance • movement is against concentration gradient • powered by ATP • typically moves ions Na, K, Ca 1a. primary active transport • ATP is used directly to move substances against a gradient • ex. Na/K pump…an exchange pump • hydrolysis of ATP causes the phosphate to attach to the protein carrier…causes the protein to change its shape so that it pumps the bound substance across the membrane • ex. Na/K pump …Carrier is a protein/enzyme called Na/K ATPase • Na is high in ECF, K is high in ICF • Na and K constantly leak thorough leakage channels…Na leaks in, K leaks out…. but it is important to return them to their proper places • Na/K pump works continuously to take Na back out of cell and K into cell 1b. secondary active transport • Na leaks into cell down its concentration gradient with use of a carrier protein (facilitated diffusion)…..this pulls/drags/cotransports glucose with it • Na and glucose movement is passive but Na has to be pumped back out into the ECF to maintain its diffusion gradient • Na/K pump uses energy/ATP to pump Na back out…to return Na to its proper place in ECF and to re-establish that concentration gradient…that high Na in ECF is important as it is that Na gradient that makes Na leak into the cell and pull glucose with it Vesicular Transport • Moving large molecules into or out of cells Endocytosis • moving substances from ECF into cell • substance is enclosed by an infolding portion of the plasma membrane, membrane pinches off and the vesicle enters the cell • lysosome degrades it and the contents is degraded or released Phagocytosis - cell eating - solid material engulfed by cell….bacteria, cell debris, nutrients - particle binds to receptors on cell surface, forms a vesicle called a phagosome, once inside the cell, fuses with a lysosome and the contents are digested Pinocytosis - cell drinking - fluid with dissolved molecules is surrounded by infolding of cell membrane - enters cell, vesicle is degraded and fluid and dissolved particles enter cell - this happens regularly as a means to sample the ECF, especially important for intestinal cells that absorb nutrients Receptor mediated endocytosis - endocytosis of specific substances….hormones, cholesterol, iron - particular substances bind to specific membrane protein receptors Exocytosis • moving substances from the interior of the cell into the ECF • ex. Hormone secretion, ejection of wastes, etc… • substances is enclosed in a vesicle, moves to plasma membrane, fuses with membrane, ruptures…contents spill into ECF Resting Membrane Potential plasma membrane is selectively permeable… • This causes some things to accumulate on each side of the membrane as they are not allowed to pass through it….some of those things …Na, K….have charges • This creates Membrane Potential/Voltage/difference in charge across the membrane • Inside of membrane is negative relative to outside (-70mV) Resting State – K+ high concentration inside cell, Na high concentration in ECF Outside…..lots of Na+ along membrane Inside…..lots of K + along membrane but not as much K+ along membrane as there is Na outside ...therefore…less + inside…so inner side of membrane is relatively negative This exists only at the membrane….the majority of the cell is neutral as is the ECF The Na and K gather at the membrane because they want to cross the membrane because of their concentration gradient How is the membrane potential established? Mainly by concentration gradient of K+ and the difference in membrane permeability to K and Na Resting state….. Membrane is a little permeable to K…leakage channels……K diffuse out a little down its gradient….inside is losing some +ve so it is becoming negative (from -70 to -90) Membrane is only a tiny bit permeable to Na so some Na will enter down its concentration gradient, this ….takes membrane back up to -70 Active transport processes maintain the membrane potential…Na/K pump works to maintain the membrane potential….. Pumps 3 Na+ out and 2 K+ in………so that K that leaked out and that Na that leaked in is stopped and they are sent back to their proper places so that strong gradient is maintained In pumping 3 Na+ out and 2 K+ in…..the inside is not becoming as +ve as the outside, less + is being pumped in, so the inside is staying relatively –ve and K+ is returning inside and Na+ outside Phys 103 Class 9 – Cell Reproduction Summary Cell Reproduction Cell life cycle = series of changes a cell goes through from formation until reproduction…….consists of: interphase and cell division Interphase = cell growth and normal activities Cell division/mitosis = cell divides into 2 cells Interphase from cell formation to cell division cell is carrying on its normal activities, in between cell divisions G1 - growing rapidly, making proteins, at end of G1, centrioles replicate to prepare for cell division S - DNA replication, cell still growing and carrying on normal activity too G2 - enzymes and proteins needed for division are made, cell still growing DNA Replication Identical copies of genetic code must be passed on to offspring before a cell can divide 1. DNA double helix unwinds 2. Enzyme separates it into 2 strands of nucleotide chains, exposing the nucleotide bases 3. Each strand is a template for a new complementary strand of nucleotides created from free floating DNA precursors floating in the nucleoplasm 4. Enzymes and DNA precursors accumulate at replication site 5. DNA polymerase (enzyme) positions complementary nucleotides along the template and links them together, creating a long chain 6. Replicated segments are joined together resulting in 2 DNA molecules formed...each DNA molecule has an old and new strand 7. Replication is over, DNA condenses to form chromatids, chromatids are attached by a centromere Cell Division Mitosis - events that delivers the replicated DNA to 2 daughter cells 4 phases – prophase, metaphase, anaphase, teophase Cytokinesis - plasma membrane is drawn inward until the cytoplasmic mass is pinched into 2 daughter cells each daughter is smaller and has less cytoplasm but is genetically identical to the mother they then enter interphase until it is their turn to divide Interphase DNA is condensed chromatin microtubules extend from centromeres centrioles replicate from one pair to 2 pairs DNA replicates Early Prophase microtubule asters extend around centrioles chromatin coils and condenses to form chromosomes - 2 identical chromatin threads (chromatids) chromatids of a chromosome are held together by a centromere centriole pairs separate from each other centrioles grow microtubules…..mitotic spindle….this pushes the centrioles farther Late Prophase centrioles still moving apart nuclear envelope disappears mitotic spindle microtubules attach to chromosome centromeres chromosomes are being pulled towards centre of cell Metaphase chromosomes line up along middle of cell Anaphase centromeres of each chromosome split and one chromatid is pulled towards one end of the cell and the other is pulled the other way each chromatid is now called a chromosome the microtubles push the poles of the cell apart, causing the cell to elongate Telophase identical sets of chromosomes are now at opposite ends of the cell chromosomes uncoil into threadlike chromatin new nuclear envelope develops from floating fragments of the original envelope spindle disappears Cytokinesis completes the division into 2 cells contractile ring of microfilaments forms at the midline and squeezes the cells apart towards opposite ends of the cell Phys 103 Class 10 – Protein Synthesis Protein Synthesis DNA’s 2 roles: replicate itself prior to cell division provides instructions for protein synthesis gene: a segment of DNA that carries instructions for creating one polypeptide chain…the sequence of ATCG nucleotides is the code of specific proteins to be made triplet: a sequence of 3 bases …a specific code for a specific amino acid ex. TTT is the DNA code for phenylalanine GGG is the DNA code for glycine the sequence of triplets in each gene is like a sentence……code for a polypeptide…specifies the type, number and order of amino acids needed to build that polypeptide chain so basically…. sequence of DNA triplets is transcribed to a sequence of mRNA codons and that is translated to a string of amino acids which form a protein one strand of DNA has a code for a particular protein (coding strand/sense strand) its complementary strand serves as a template template strand is copied to produce a strand identical to the coding strand (with the exception of the A and U thing) so the template is actually copied to create the mRNA ex. phenylalanine DNA triplet = TTT (AAA is template) RNA codon = UUU ex. proline DNA triplet = CCT (GGA is template) RNA codon = CCU Role of RNA DNA information can only be used if it s decoded……needs a “decoder” DNA stays in the nucleus and most protein is made on ribosomes in the nucleus….needs a “messenger” RNA does the decoding and messenging RNA……similar to DNA but is single strand and has uracil instead of thymine 3 types of RNA work together to carry out DNA’s instruction transfer RNA…..tRNA…small molecule that brings amino acids to ribosome ribosomal RNA….rRNA…constructs the ribosome messenger RNA…mRNA…carries the info from sense strand of DNA to ribo 2 stages involved in polypeptide synthesis… transcription…DNA’s information is encoded in mRNA translation…information carried in RNA is decoded and used to assemble polypeptides Transcription transfer of information from a DNA gene’s base sequence to the complementary base sequence of an mRNA molecule mRNA detaches from DNA, leaves the nucleus RNA polymerase unwinds 16-18 base pairs of DNA…then incoming ribonucleotides are aligned with complementary DNA bases on the template strand and joins the RNA nucleotides together ex. DNA template triplet AGC…..the mRNA sequence synthesized at that site will be UCG (the coding triplet would have been TCG) Translation language of nucleic acid (base sequence) is translated into the language of proteins (amino acid sequence) occurs in cytoplasm involves mRNA, tRNA and rRNA in cytoplasm, mRNA binds to small ribosomal subunit by pairing to rRNA tRNA comes and transfers amino acids to the ribosome, maneuvers the amino acid into the proper position as specified by the mRNA codon tRNA has amino acid bound to one end , anticodon at other end….3 base sequence complementary to the mRNA codon calling for the amino acid carried for that tRNA ex. mRNA codon UUU phenylalanine….tRNA carrying phenylalanine will have anticodon AAA ribosome holds the tRNA and mRNA close together to coordinate the coupling of codons and anticodons and positions the next amino acid for addition to the growing chain initiation of translation…… mRNA attaches to small ribosomal subunit large ribosomal subunit attaches to the smaller one…forms a functional ribosome with mRNA positioned in the groove between the two subunits ribosome slides the mRNA along, bringing a codon into position to be read by a tRNA tRNAs continually transfer their amino acids onto the growing chain and then the tRNAs move along and exit from the ribosome polypeptide is then released from the ribosome and the ribosome subunits separate EPITHELIAL TISSUE Simple Squamous for filtration or exchange of substances by diffusion kidney filtration membrane, alveoli walls in lungs, lines heart and blood vessels, lines ventral body cavities and covers organs Simple Cuboidal for secretion and absorption found in kidney tubules, ducts of glands, ovaries Simple Columnar for absorption and secretion, has microvilli….for absorption, goblet cells …secrete mucus in digestive tract, some have cilia…uterus and bronchi Stratified Squamous protection forms outer layer of skin and extends a little into all body openings, epidermis…keratinized Stratified Cuboidal rare – sweat glands and mammary glands Stratified Columnar rare – pharynx, urethra Transitional cells stretch and permit distension bladder Pseudostratified Columnar absorption and secretion, may have goblet cells…secretes mucus, may have cilia respiratory tract CONNECTIVE TISSUE Areolar Connective Tissue supports and bind other tissues, holds fluid, infection defense, stores nutrients widely distributed in body, wraps blood vessels, glands, nerves, forms subcutaneous tissue that cushions skin and attaches skin to underlying structures Adipose Tissue fuel reserve, insulation, protection accumulates in subcutaneous tissue, surrounds kidneys, behind eyes, accumulates at genetically determined fat deposits such as abdomen and hips, located around organs Reticular Connective Tissue forms a framework that supports blood cells in lymph nodes, spleen, bone marrow nodes, spleen, bone marrow Dense Regular provides strength and resistance to tension where tension is exerted in a single direction tendons and aponeuroses, fascia, ligaments Dense Irregular forms sheets in areas where tension is exerted from many directions skin…dermis, fibrous joint capsules, fibrous coverings of some organs…kidneys, bones, cartilage, muscles, nerves Hyaline Cartilage firm support, some pliability articular cartilage, tip of nose, connects ribs to sternum, supports respiratory passages, embryonic skeleton, epiphyseal plates in children Elastic Cartilage where strength and stretchability is needed external ear, epiglottis Fibrocartilage where strong support and ability to withstand heavy pressure needed intervertebral discs, knee menisci Bone supports and protects body structures, cavities for fat storage and synthesis of blood cells Blood carries nutrients, wastes, gases and other substances MUSCLE TISSUE responsible for body movements Skeletal - support the skeleton and allow movements of bones at joints Cardiac - in walls of heart, contraction propels blood through blood vessels Smooth - in walls of hollow organs, squeezes substances through the organs NERVOUS TISSUE regulates and controls body functions neurons – generate and conduct nerve impulses supporting cells – nonconducting cells, support, insulate, protect neurons Metabolism metabolism = all the biochemical reactions that occur in the body catabolism - breaking down of complex substances……fat, CHO, proteins….into simpler ones…fatty acids and glycerol, glucose, amino acids, they can be further broken down in cells to acetyl coA and then used to make energy ….ATP….. anabolism - building of substances….cell components, organelles, cells, tissues, enzymes, proteins, membranes cells extract energy from the breakdown of foods (catabolism) and use energy to build (anabolism) basically…… energy is released (due to transferring of electrons) in the process of breaking down nutrients (catabolism) to its it most basic components….C, H, O, N the energy is stored in ATP in high energy chemical bonds between the P molecules the cell then uses that ATP for building (anabolism) cell components, for muscle contraction, for membrane transport Energy Usage and ATP when nutrients are broken to their simple components (catabolism) electrons are transferred from molecules and trapped in the bonds of ATP ATP is a high energy molecule……stores energy in the chemical bonds of P molecules ATP releases its energy to do work…..does this by phosphorylation…enzymes shift high energy phosphate groups from ATP to other molecules which phosphorylates them and causes them to increase in activity, produce motion or do work ATP with the help of an enzyme changes to ADP and gives the P and energy from that bond to another molecule Cellular Respiration the group of catabolic reactions where food fuels especially glucose are broken down in cells and some of the energy released is captured to form ATP nutrients are broken down and are oxidized……O2 is added to them and they are oxidized they lose electrons to the O2 molecule those electrons will be transferred in a series of reactions and the energy will be captured as ATP specific enzymes allow this to occur …purpose is to harvest electrons from the energy rich molecules of glucose…..and use those electrons to be stored in the phosphate bonds of ATP Redox Reactions oxidation – reduction reactions these types of reaction occur during the process of cellular respiration oxidation = adding oxygen to another element…causes a change in the element ……..adding O2 causes 2 electrons to be removed and given to the O2 ……..removing 2H causes 2 electrons to be removed so the proper definition is…… oxidation is the gain of oxygen or loss of hydrogen (both result in electrons being removed from the original molecule) so…..the oxidized substance loses electrons ….or nearly loses the electrons…recall covalent bonds……they don’t actually lose the electrons… they share them but oxygen is greedy and the electrons that are being shared spend more time with the oxygen molecule.....with hydrogen…when hydrogen is part of a molecule of other stuff, its lone electron is pulled to hang out with the other atoms in the molecule, but when H splits from the molecule……it pulls its lone electron with it. with food breakdown in cells….food is oxidized in a step by step process step by step removal of pairs of hydrogen molecules occurs…in removing H molecules it pulls its electron with it…..so pairs of electrons are being removed in a step by step process the eventual result is CO2 and H2O………………..from……glucose…..C6H12O6 in the end the removed electrons will combine with O2 to form H2O so…..one substance is losing electrons…..it is oxidized …the food item those electrons do not just float free….another molecule must pick them up so……one substance gains electrons after one loses them the substance that gains the electrons is “reduced”……getting more negative so the reactions are called oxidation-reduction or redox bottom line: oxidized = loses energy reduced = gains energy since energy rich electrons are transferred from one substance to the next so basically…..food is oxidized and the energy is transferred to a series of other molecules and ultimately to ADP to make ATP Enzymes enzymes are needed to make this happen…help with H+ removal the enzymes need help from coenzymes Coenzymes the coenzymes can be hydrogen/electron acceptors…NAD+ and FAD (f NAD will accept those H and reduce to NADH2 FAD will accept those H and reduce to FADH2 Processes Involved in Cellular Respiration 1. Glycolysis breaking down/oxidizing glucose to make: pyruvic acid or lactic acid a very small amount of ATP 2. Formation of Acetyl coA pyruvic acid is converted to acetic acid, added to coA to make acetyl coA 3. Krebs cycle in mitochondria acetyl coA undergoes a series of conversions where pairs of electrons are removed and passed to an acceptor molecule….NAD or FAD FAD and NAD carry the electrons to the ETC to make ATP 4. ETC electrons removed from food molecules in processes 1, 2, 3 are passed along a series of electron acceptors H is pumped across the mitochondrial membrane…gradient pulls it back in and ATP is produced as these electrons move and their energy is captured O2 will accept some H to make H2O Mechanisms of ATP Synthesis energy/electrons is freed up during cellular respiration and it is captured to make ATP this occurs in 2 different ways…substrate level phosphorylation and oxidative phosphorylation Substrate Level Phosphorylation high energy phosphates are transferred directly from phosphorylated substrates (such as glyceraldehyde phosphate) to ADP the P bound to the other substrate is very unstable so it will find an ADP and bind to that to be more stable this happens in glycolysis and krebs….produces a very small amount of ATP Oxidative Phosphorylation: more complicated, but more ATP is created this way done by electron transport proteins energy released in oxidation of food is used to pump H+ protons across the mitochondrial membrane to create a steep concentration gradient for protons across the membrane through a membrane channel called ATP synthase…some of this gradient energy is captured and used to attach phosphate to ADP Sites of Cellular Respiration glycolysis – cytoplasm Krebs – mitochondria Acetyl coA – mitochondria ETC – mitochondria Energy Sources for Cellular Respiration CHO starch, glycogen, disaccharides, simple sugars can be used in glycolysis can be stored as glycogen …..glycogenesis stored glycogen can be converted back to glucose….glycogenolysis can be stored as fat…when glycogen stores are full ….lipogenesis can be made from glycerol, lactate, amino acids…gluconeogenesis mobilized from triglycerides (one type of fat) ….that are stored or eaten TG splits into 3 fatty acids and glycerol used for fuel…lipolysis used for fuel if glucose levels are low used for fuel if metabolic demands increase beyond what glucose can provide used for fuel by liver, resting skeletal muscle, adipocytes fatty acid converts to acetyl coA…enters krebs cycle, ETC….beta oxidation glycerol enters glycolysis as glyceraldehyde……pyruvate…acetylcoA….Krebs… LIPIDS AMINO ACIDS body prefers to use them for protein synthesis can be used as energy if body has excess amino acids or if glucose and fat supply is exhausted enters the pathway at Krebs cycle as pyruvic acid, acetyl coA and Krebs cycle intermediates can be converted to fat….lipogenesis can be converted to new glucose….gluconeogenesis Carbohydrate Metabolism all CHO are transformed to glucose glucose enters cells with the help of insulin glucose can be used to make ATP (glycolysis) glucose can be stored as glycogen (glycogenesis) when glucose enters cells….. immediately phosphorylated to Glucose 6 Phosphate (G6P) a P is taken from an ATP molecule this can not be reversed, most cells lack the enzyme needed to reverse this….therefore glucose is trapped inside the cells….and since G6P is different than glucose…..intracellular glucose levels are therefore kept low (since it is immediately converted to G6P)….this maintains a gradient for glucose to enter the cells…..good thing (intestine, kidney and liver can reverse this process) glucose can continue on the glycolysis path or convert to glycogen for storage Glycolysis series of 10 chemical reactions occurs in the cytoplasm glucose is converted to 2 pyruvic acid molecules one 6 carbon molecule is converted to two 3 carbon molecules anaerobic process…does not use oxygen…will occur in the presence or ansence of oxygen 3 major phases 1. Activation of Sugar 2. Cleavage of Sugar 3. Oxidation and ATP Synthesis final product = 2 molecules of pyruvic acid 1. Sugar Activation glucose is phosphorylated to Glucose-6-Phosphate (G6P) G6P changes to Fructose-6-Phoshate (F6P) F6P is phosphorylated to F-1,6-Bisphosphate 2 ATP used for those 3 steps….each time a P is added…..uses and ATP 2. Sugar Cleavage F-1,6-Bisphosphate splits into two 3C molecules (G3P) or (DHP) (glyceraldehyde 3 phosphate or dihydroxyacetone Phosphate) 3. Oxidation and ATP Synthesis six steps the two G3P are oxidized…2H+ is removed from each….picked up by 2NAD+ P is then attached to each G3P later the P are cleaved off and 4 ATP are created final product is: 2 pyruvic acid 2 NAD that picked up 2H+ each….they are reduced to NADH2 2 ATP molecules (2 were used in phase 1, 4 were made in phase 3) glucose was C6H12O6 pyruvate is C3H4O3 and C3H4O3 so……4 H missing……bound to NAD Products of Glycolysis ATP 4 are produced…step 7 and step 10 2 were used….step 1 and step 3 net production = 2 ATP NADH2 2 NADH2 are made …step 6 if O2 present……NADH2 will carry those H to ETC…..in ETC….each will produce 2 ATP if O2 no O2 present…..NADH2 will offload these H onto the pyruvic acid….makes lactic acid PYRUVIC ACID 2 are produced if no O2 present…..converts to lactic acid…..takes the H from the NADH2 lactic acid leaves the cell, enters blood, travels to liver to be reconverted to glucose (gluconeogenesis) the freed up NAD can pick up more H as glucose is being broken down so that glycolysis can continue ** no O2 situation…strenuous exercise….need to make O2 fast….need glycolysis so to make ATP fast……need to have NAD to pick up the H and then need to dump the H off somewhere and need to pick up more. If O2 was present, the NADH2 could dump the H in the ETC (because the H would combine with the O2 to make H2O)…but no O2 avail so NADH2 dumps the H onto pyruvic acid and is free and glycolysis can continue. If O2 present, pyruvic acid is converted to acetyl coA and it enters the krebs cycle……and the NADH2 enters the ETC Functions of Glycolysis 1. produce ATP 2. produce pyruvic acid for oxidation in mitochondria 3. release H to be used for production of ATP in the ETC Specific Reactions Activation of Sugars 1. 2. 3. glucose (6C) ATP needed to add a P glucose-6-phosphate (6C-P) changes structure fructose-6-phosphate (6C-P) ATP needed to add a P fructose-1,6-bisphosphate (P-6C-P) Splitting of Sugars 4. fructose-1,6-bisphosphate (P-6C-P) sugar splits into 2 glyceraldehyde-3-phosphate (3C-P) dihydroxyacetone phosphate (P-3C) Oxidation reactions 5. 6. 7. glyceraldehyde 3-phosphate (3C-P) 2H+ removed, picked up by NAD to form NADH2 to go to ETC 1,3-bisphosphoglycerate (P-3C-P) phosphate removed to create ATP 3-phosphoglycerate (3C-P) changes structure glyceraldehyde 3-phosphate (3C-P) 2H+ removed, picked up by NAD to form NADH2 to go to ETC 1,3-bisphosphoglycerate (P-3C-P) phosphate removed to create ATP 3-phosphoglycerate (3C-P) changes structure 8. 9. 2-phosphoglycerate (3C-P) 2-phosphoglycerate (3C-P) changes structure phosphoenolpyruvate (3C-P) phosphate removed to create ATP pyruvate (3C) changes structure phosphoenolpyruvate (3C-P) phosphate removed to create ATP pyruvate (3C) Activation of Sugars 1. 2. 3. glucose (6C) ATP needed to add a P glucose-6-phosphate (6C-P) changes structure fructose-6-phosphate (6C-P) ATP needed to add a P fructose-1,6-bisphosphate (P-6C-P) Splitting of Sugars 4. fructose-1,6-bisphosphate (P-6C-P) sugar splits into 2 glyceraldehyde-3-phosphate (3C-P) dihydroxyacetone phosphate (P-3C) Oxidation reactions 5. 6. 7. 8. 9. glyceraldehyde 3-phosphate (3C-P) 2H+ removed, picked up by NAD to form NADH2 to go to ETC 1,3-bisphosphoglycerate (P-3C-P) phosphate removed to create ATP 3-phosphoglycerate (3C-P) changes structure 2-phosphoglycerate (3C-P) changes structure phosphoenolpyruvate (3C-P) phosphate removed to create ATP pyruvate (3C) glyceraldehyde 3-phosphate (3C-P) 2H+ removed, picked up by NAD to form NADH2 to go to ETC 1,3-bisphosphoglycerate (P-3C-P) phosphate removed to create ATP 3-phosphoglycerate (3C-P) changes structure 2-phosphoglycerate (3C-P) changes structure phosphoenolpyruvate (3C-P) phosphate removed to create ATP pyruvate (3C) Activation of Sugars 1. ATP needed to add a P………………..…………1 ATP used 2. changes structure 3. ATP needed to add a P……………………………1 ATP used Splitting of Sugars 4. sugar splits into 2 Oxidation reactions 5. NADH2 made ……………………………………… 1 NADH2 made NADH2 made ……………………………..………...1 NADH2 made 6. phosphate removed to create ATP………………..1 ATP made phosphate removed to create ATP…………………1 ATP made 7. changes structure changes structure 8. changes shape changes shape 9. phosphate removed to create ATP…………………..1 ATP made phosphate removed to create ATP…………………..1 ATP made total…… 2 ATP used 2 NADH2 made 4 ATP made so the story so far…………….. 1 molecule of glucose broken down 2 ATP used to add P to glucose glucose modified several times glucose splits phosphate is removed and 2 ATP are made hydrogen is removed and picked up by NAD to make 2 NADH2 to go to ETC (if O2 is present) to make ATP glucose is modified several more times phosphate is removed and 2 ATP are made 2 pyruvic acid molecules are made Fate of Pyruvic Acid Aerobic vs. Anaerobic conditions 1. If no O2 present…..Anaerobic conditions pyruvate is converted to lactic acid the H+ removed during glycolysis that was picked up by NAD is released from NAD and reattached to the pyruvate to form lactic acid the lactic acid leaves the cell, enters the blood taken to the liver for gluconeogenesis…..convert into glucose why does this happen? to use glucose for fuel, a few conditions must exist…… 2 ATP available for initial few steps NAD available to pick up the H 4 ADP available to pick up P to make ATP NADH2 needs to dump its hydrogen off in order to be available to pick up more during the process of glycolysis ideally…..O2 would be available and that 2H would combine with the O2 to make H2O but……..anaerobic conditions….no O2 available…ie. strenuous exercise……burning glucose…it is a quick and easy fuel to use. Fat and amino acid burning needs O2 no O2 available so……the pyruvic acid can accept the H to allow the process to continue without O2 the NAD are now freed up to accept more H and more glucose can breakdown for fuel 2. If O2 present pyruvic acid is converted to acetyl coA the NADH2 can take that hydrogen to the mitochondrial membrane and dump it off so that it can eventually combine to the O2 to make H20. the freed up NAD can return to glycolysis to pick up more H since the pyruvic acid does not need to pick up the H+, it wont change to lactic acid the pyruvic acid will continue on the oxidative pathway. the pyruvic acid enters the mitochondria and forms acetyl coA Krebs Cycle and ETC so the story so far………Glycolysis…….. 1 molecule of glucose broken down 2 ATP used to add P to glucose glucose modified several times, glucose splits phosphate is removed and 2 ATP are made hydrogen is removed and picked up by NAD to make 2 NADH2 to go to ETC (if O2 is present) to make ATP more phosphate is added glucose is modified several more times phosphate is removed and 2 ATP are made 2 pyruvic acid molecules are made Fate of Pyruvic Acid 1. If no O2 present…..Anaerobic conditions…pyruvate is converted to lactic acid the H+ removed during glycolysis that was picked up by NAD is released from NAD and reattached to the pyruvate to form lactic acid NADH2 needs to dump its hydrogen off in order to be available to pick up more during the process of glycolysis ideally…..O2 would be available and that 2H would combine with the O2 to make H2O but……..anaerobic conditions….no O2 available…ie. strenuous exercise……burning glucose…it is a quick and easy fuel to use no O2 available so……the pyruvic acid can accept the H to allow the process to continue without O2 the NAD are now freed up to accept more H and more glucose can breakdown for fuel 2. If O2 present pyruvic acid is converted to acetyl coA the NADH2 can take that hydrogen to the mitochondrial membrane and dump it off so that it can eventually combine to the O2 to make H20. the freed up NAD can return to glycolysis to pick up more H since the pyruvic acid does not need to pick up the H+, it wont change to lactic acid the pyruvic acid will continue on the oxidative pathway. KREBS CYCLE Formation of Acetyl CoA occurs in mitochondria if O2 is available pyruvate enters mitochondrial matrix and is converted to acetyl coA in that process, a carbon is removed…released as CO2 and 2H are removed….picked up by NAD…..taken to ETC… acetic acid is result, coenzyme A joins acetic acid….forms acetyl coA recall…..2 pyruvate molecules made….therefore each undergoes change to acetly coA and each produces a NADH2 so………the story so far……………….. Glycolysis 2 ATP used 2 NADH2 made 4 ATP made 2 pyruvic acid molecules made Acetyl coA formation 2 NADH2 made Krebs Cycle Acetyl CoA enters Krebs cycle the CoA takes the 2 carbon acetic acid to combine it with 4 carbon oxaloacetic acid to make 6 carbon citric acid citric acid enters cycle…8 reactions which rearrange the molecule…carbons removed, hydrogens removed acetic acid is completely gone by the end of the cycle and the oxaloacetic acid is ready to pick up another acetic acid what is made…..2 CO2, 3NADH2, 1FADH2, 1ATP each pyruvic acid yields….. 1 CO2 …….in acetyl CoA formation 2 CO2 …….in krebs 1NADH2 ….in acetyl CoA formation 3NADH2 … in krebs 1 FADH2 … in krebs 1ATP recall……2 pyruvic acid molecules come from one glucose so….. 2NADH2 from acetyl coA 6NADH2 from krebs 2FADH2 from krebs 2ATP from krebs Electron Transport Chain and Oxidative Phoshorylation the H removed during oxidation of food in glycolysis and krebs are combined with oxygen and the energy released during those reactions is harnessed to attach P to ADP protein-metal complexes in the mitochondrial membrane are alternately reduced and oxidized by picking up electrons and passing them on to the next complex in sequence the first complex accepts H from NADH2…oxidizing it to NAD FADH2 transfers its H further along the H splits into its protons and electrons the electrons are shuttled along the membrane from one acceptor to the next, the shuttling of electrons provides energy to pump protons out to the intermemb space the protons escape into the matrix and then are sent across the membrane into the intramembrane space the electrons are delivered to O2 to create H2O the proton movement creates a gradient (proton motive force) that is higher in the intramembrane space than in the matrix and it creates a voltage gradient that is positive in the intramembrane space and negative in the matrix these conditions strongly attract H+ back into the matrix H+ cannot cross the membrane …impermeable enzyme-protein complex/carrier…..ATP synthase is freely permeable to H+ protons go through here…create an electrical current and ATP synthase harnesses this electrical energy to attach a P to ADP to form ATP the H combines with the electrons and O2 to make H2P Total ATP Production one molecule of glucose…….. 4ATP from substrate level …….2 glycolysis, 2 krebs each NADH transfering 2H to ETC contributes enough energy to the proton gradient to generate 3 ATP each FADH2 transfers 2H to ETC a little father along…..generates 2 ATP 2 NADH from glycolysis…….6 ATP 8 NADH from krebs…………24 ATP 2 FADH from krebs…………..4 ATP …….38ATP but…..the 2NADH formed in glycolysis……in cytoplasm….outside membrane……cant cross the membrane…….needs ATP to carry each across so…….deduct 2 ATP……total = 36 Again…… glycolysis 2 ATP made …………………………….…….….2 ATP 2 NADH2 made ……………………….……….…4 ATP acetyl coA formation 2 NADH2 made ……………………….………….6 ATP krebs 2 ATP made………………………………………. 2 ATP 6NADH2 made ……………………………………18 ATP 2 FADH2 made ……………………………………4 ATP 36 ATP total Other Metabolic Processes glycolysis - use glucose to make ATP glycogenesis - make glycogen glycogenolysis - breakdown glycogen gluconeogenesis - making glucose from noncarbohydrates lipolysis (beta oxidation and glycerol breakdown)– breakdown fat lipogenesis - make fat Glycogenesis excess consumption of glucose doe not lead to unlimited ATP production cant store large amounts of ATP rising ATP levels In cells inhibits glycolysis and initiates the storage of glucose we store glucose as glycogen or fat….body can store more fat than glycogen Glycogenesis = making glycogen from glucose when ATP levels are high…don’t need to make more…..dont need to break down the glucose to make more ATP glucose enters cells from blood ATP used to add P…..this forms glucose-6-phosphate glucose-6-phosphate changes to glucose-1-phosphate phosphate is removed as Glycogen Synthase attaches the glucose to the growing glycogen chain this happens in liver and muscle cells so……….. glucose in blood…need to make ATP……….glycolysis……make ATP excess glucose in blood…don’t need more ATP….glycogenesis…make glycogen Glycogenolysis when blood glucose is low breakdown glycogen and change it into glucose glycogen phosphorylase cleaves a glycogen off the chain and adds a phosphate to change it to glucose-1-phosphate this is then converted to glucose-6-phosphate enters glycolysis liver and kidney cells have glucose-6-phosphatase……removes the phosphate and turns it into glucose….glucose can enter the blood….therefore the liver can do this and can provide blood glucose for other organs to use when blood sugar levels drop Gluconeogenesis making glucose from non-CHO…glycerol, amino acids, lactic acid in liver when dietary glucose is low, and when glucose reserves are depleted, and when blood glucose is dropping glycerol and fatty acids…glycolysis processe reverses….glycerol and fatty acids enter glycolysis and krebs (as G3P, and acetyl coA) lactic acid…Cori-cycle in liver, lactic acid is changed to glucose delivered to muscle and other organs during exercise or starvation in muscle, lactic acid is made, enters blood, to liver, enters liver cells, changes to pyruvic acid (the 2H removed), pyruvate goes through reverse glycolysis, gets to G-6P….needs glucose-6-phosphatase to remove the P and convert to glucose free glucose enters blood, travels to muscles Lipid Metabolism Oxidation of Glycerol and Fatty Acids eat fat/triglycerides….they are made of glycerol and fatty acids when glucose levels are low triglycerides will be used as energy, also used if increased metabolic demands are placed on the body Lipolysis triglyceride split into glycerol and fatty acids Glycerol Metabolism glycerol converts easily to glyceraldehyde phosphate…glycolysis intermediate one glyceraldehyde molecule will produce about ½ the amount that a glucose will……18ATP recall one G3P in glycolysis will make: 1NADH2, 2 ATP, pyruvic acid pyruvic acid enters krebs: 1NADH2 in conversion to acetyl coA 3 NADH2 and 1 FADH2 , 1 ATP total……19ATP Beta Oxidation initial phase of fatty acid oxidation, in mitochondria fatty acid chains are broken into 2 carbon acetyl CoA fragments to the long fatty acid chain… CoA is added, ATP is used to add a P, 2FADH2 made, 2NADH2 made the 2 end carbons (alpha and beta) are removed as acetyl CoA…enters krebs recall..…from acetyl CoA....3 NADH2, 1 FADH2 and 1 ATP made so a 2 carbon fatty acid fragment makes: 1 FADH2……………2 ATP 1 NADH2……………3 ATP 3 NADH2 (acetyl coA in krebs)………9 ATP 1 FADH2 (acetyl coA in krebs) ………2 ATP 1 ATP (acetyl coA in kebs)……………1 ATP so… lipids can produce tons of ATP since: 2 carbons of a fatty acid/acetyl coA makes 17 ATP each fatty acid can be 18 carbons long…..9 acetyl CoA 3 fatty acids make a triglyceride……27 acetyl CoA glycerol makes 19 ATP but…… fat stores are harder to access, can’t provide ATP quickly so if start exercising….switch to glucose burning……access it fast the glycerol changes to glyceraldehyde……can be used for gluconeogenesis since that reaction can be reversed the fatty acids change to acetic acid….can not be used for gluconeogenesis since the reaction is not reversible past pyruvic acid Lipogenesis when glycerol and fatty acids are eaten, if not needed immediately for energy, they are recombined into triglycerides and stored if cellular ATP and glucose levels are high…..dont need to break down fat excess ATP leads to accumulation of acetyl coA and G3P since you don’t need to use them to make more ATP….dont need glycolysis (G3P) or krebs (acetyl coA) to occur Acetyl coA molecules join together to make fatty acid chains glucose therefore is easily converted to fat……goes through glycolysis…to pyruvate……to acetyl coA……if too much or too much ATP…..acetyl coA to fatty acid G3P changes to glycerol….added to the fatty acids….makes TG Amino Acid Metabolism Protein Metabolism eat protein…into blood…into cells to replace tissue proteins excess protein eaten and available…use for energy or convert to fat Oxidation of Amino Acids amino acids must be deaminated…amine group NH2 removed then converted to pyruvic acid or a keto acid in krebs 1. Transamination transfer of amine group to alpha ketoglutaric acid (a krebs intermediate) the original amino acid is now a keto acid (used as a krebs intermediate) the keto acid is now glutamic acid (an amino acid) 2. Oxidative Deamination in liver amine group on glutamic acid is removed as ammonia (NH3) and alpha ketoglutaric acid is regenerated (used as a krebs intermediate) liberated NH3 is combined with CO2 to make urea and water urea to blood to urine 3. Keto Acid modification keto acids resulting from transamination is altered to produce molecules to enter krebs…pyruvic acid, acetyl CoA, alpha ketoglutaric acid, oxaloacetic acid deaminated amino acids can convert to pyruvate and be reconverted to glucose and contribute to gluconeogenesis Thermoregulation maintenance of a constant internal temperature balance between heat production and heat loss temp 36.5 to 37.5 celsius is ideal, maintained between 35.8-38.2 core temp is precisely regulated blood is the heat exchange regulator between core and shell if shell is warmer than environment….lose heat from body as warm blood flows through skin capillaries if shell is colder than environment….must conserve the heat in body….blood bypasses the skin…reduces heat loss, allows shell temp to fall toward environment temp Metabolic Rate body’s rate of energy output heat produced by all the chemical reactions and mechanical work of the body BMR a standardized measure of metabolic rate in a relaxed state energy needed to perform most essential activities 70kg adult approx 60-72 kcal/hr for 70kg person Factors Affecting MR body surface area…increased surface area = increased BMR age…young = higher BMR….need for growth, more muscle tissue gender…males = higher BMR…more muscle tissue stress…adrenaline released…..increases fat catabolism hormones…thyroid hormone, testosterone Heat Exchange heat travels down gradient from warm to cold 1. radiation infrared waves radiate from body warm objects transfer heat to cool objects 2. conduction heat transfer through direct contact 3. convection warm air rises away from body and is replaced by cooler air 4. evaporation water evaporates because the water molecules absorb heat and become energetic/vibrate fast enough to escape as gas (water vapor) water absorbs a lot of heat before vaporizing, when it evaporates it removes heat from the body insensible water loss evaporation from lungs, mucosa of mouth and skin…unnoticeable…insensible sensible water loss when body temp rises and sweating increases Role of Hypothalamus heat loss and heat promotion are integrated in the hypothalamus afferent impulses come from peripheral thermoreceptors in the skin/shell and from central thermoreceptors in the blood vessels/core acts like a thermostat responds to signals to increase heat production or heat loss Heat Promoting Mechanism external temp or blood temp is low response: 1. constriction of cutaneous blood vessels blood bypasses the skin and stays in the core skin is separated from the core by a layer of insulating fat….so heat in the core can not escape and not much heat is lost from the shell since it is all in the core shell temp drops toward external temp…ok for a short time 2. shivering increased muscle tone occurs which stimulates stretch receptors in antagonist muscles this increases muscle activity….heat production 3. increase in metabolic rate epinephrine released by adrenals due to SNS stimulation…..stressful situation causes elevated metabolic rate which increases heat production 4. enhanced thyroxine release hypothalamus stimulates thyroid to release thyroid hormone mostly for the gradual temp change as seen in change of seasons Heat Loss Mechanism protects the body from overheating when core temp rises above normal the heat promoting mechanisms in the hypothalamus are inhibited and heat loss centre triggers: 1. dilation of cutaneous blood vessels the motor fibers that innervate skin blood vessels are inhibited so they dilate warm blood fills the blood vessels and as skin vessels are near the surface of the skin, heat is lost by radiation, conduction, convection 2. enhanced sweating extremely overheated or if external temperature is so hot that heat cannot be lost by other methods, evaporation is necessary Vitamins potent organic compounds, needed in minute amounts for growth and good health, not used for energy are crucial in helping the body use nutrients most function as coenzymes, help enzymes accomplish chemical tasks Water Soluble Vitamins B complex, C absorbed along with water in GI tract excess is excreted in urine in about an hour Fat Soluble Vitamins A, D, E, K bind to ingested fats and are absorbed along with fat store in body….excess can lead to toxicity B1 – thiamine role: metabolism of pyruvic acid and other keto acids in CHO and protein metabolism, helps with synthesis of ribose and deoxyribose, helps with synthesis of acetylcholine (neurotransmitter) deficiency: beriberi…polyneuritis, cardiac failure, GI disorders, lack of coordination B2- riboflavin role: coenzymes FAD, FMN, involved in oxidation of CHO and fat…oxidatic phosphorylation deficiency: epithelial and mucosal deterioration, photophobia, cheliosis, scaly dermatitis at angles of nose, keratitis of cornea B3 – niacin role: coenzyme NAD, NADP, involved in oxidation of CHO and fat…oxidative phosphorylation deficiency: Pellegra - muscle weakness, poor gland secretion, diarrhea, dermatitis, dementia excess: megadose….hyperglycemia, vasodilation, tingling, liver damage B5 - pantothenic acid role: forms CoA…..needed to make acetyl CoA deficiency: loss of appetite, depression, muscle spasms B6- pyridoxine role: involved in transamination, hemoglobin synthesis, glycogenesis deficiency: seizures, dermatitis, nausea B7 – Biotin role: forms several enzymes for CHO, fat, pro metabolism, fatty acid synthesis, amino acid synthesis, glycogen synthesis, growth of hair, skin, oil glands, red blood cells deficiency: dermatitis, tongue soreness, anemia, depression B9 - Folic Acid role: synthesis of amino acids, DNA, cell growth, reproduction, dvmt of neural tube deficiency: anemia, impairement of cell division, diarrhea, neural tube defects B12 - cyanocobalmin role: formation, growth and maturation of RBCs deficiency: pernicious anemia = megaloblastic anemia…..RBCs get huge, lack DNA to divide, huge RBCs cant leave the bone marrow, so circulating RBC levels are low C - ascorbic acid role: antioxidant, connective tissue/collagen formation, resistance to infection, role in growth of connective tissue, bone, teeth, role in wound and bone healing deficiency: poor healing, poor tooth and bone growth, scurvey Fat Soluble Vitamins A - retinol role: growth, development of eye pigments/photoreceptors, integrity of skin and mucosa deficiency: blindness, epithelia changes, dry skin, dry eyes, cloudy cornea excess: nausea, vomiting, hair loss, joint pain etc. D – calciferol role: aids calcium absorption from GI and deposits it in bone, for blood clotting, bone formation deficiency: faulty bone mineralilzation…weak bones, rickets…..children, osteomalacia in adults…weak, soft bones excess: nausea, vomiting, cardiac and renal damage E – tocopherol role: antioxidant, prevents oxidation of unsaturated fatty acids, neutralizes free radicals – prevents damage to cell membranes deficiency: hemolysis of blood cells, fragile capillaries excess: slow wound healing, increased clotting time K role: blood clotting deficiency: bruising