Download Test one

TERMINOLOGY
Anatomy
Form of organism
Ana = up, Tome = to cut
Physiology
Physis = nature, Logia = to study
Iris – rainbow
Autopsy
Auto = self, opsis = to view
Function
HOMEOSTASIS
Homeo = same, Stasis = Still
 Maintain a stable internal environment
 e.g. Body temperature (98.6°), Heart rate (72beats/min), pH balance
 Consumes most metabolic energy of all processes
REQUIRMENTS FOR HOMEOSTASIS
 1. Receptors – Provide information about environment
 Thermoreceptors –detect temperature
 2. Control Center with Set point
 Control Center = sets the range at which the value is maintained
 Hypothalamus = Control Center
 Set point = range of values
 98.6°F = set point
 3. Effectors
 Muscles or glands
 Responds to input from control center
 Alters conditions
 e.g. Sweat glands secrete sweat to cool body
Example of Homeostatic Mechanism
EXAMPLES
Example of Homeostatic Mechanism
 Stimulus = hot environment → Body temperature increases →
Detected by thermoreceptors (receptors) → info into hypothalamus (control center)
→ Hypothalamus detects deviation from body temp (set point) →
output signal to sweat glands (effectors) → Sweat glands secrete sweat →
response = body temp cools → Stimulus decreases
HOMEOSTASIS
TWO TYPES OF FEEDBACK
Negative Feedback = response to decrease the deviation from a set point
 Most homeostatic mechanisms rely on negative feedback
Positive Feedback = response to increase deviation from set point
 Short lived and uncommon
 e.g. Child birth
CHARACTERISTICS OF LIFE
•
Organized system
•
1 or more cells, humans have 50-100 Trillion cells
•
Reproduction
•
Consumes energy, usually ATP
•
Maintains homeostasis
•
Growth
REQUIREMENTS TO MAINTAIN LIFE
•
Water (H2O) – Transportation & required for metabolic processes
•
Food – energy & building blocks
•
Oxygen – required to release energy from metabolic processes
•
Heat – energy, regulates metabolic reactions
•
Pressure – force, for breathing & circulation
LEVELS OF ORGANIZATION
Subatomic Particles
Protons, Neutrons, Electrons
↓
Atom
Hydrogen, Oxygen, Carbon
↓
Molecules
H2O (water), C6H12O6 (Glucose)
↓
Macromolecules
Proteins, Nucleic Acids, Polysaccharides
↓
Organelles
Mitochondria, Golgi Apparatus
↓
Cell
Neuron, Muscle Cell, Osteocyte
↓
Tissue
Neural tissue, Epithelial Tissue, Bone tissue
↓
Organ
Liver, Stomach, Brain
↓
Organ System
Digestive, Skeletal, Cardiovascular
↓
Organism
Human
CHEMISTRY
COMMON TERMS
Common Terms
Biochemistry = chemistry of living things
Matter = Anything that has mass and takes up space
Solids, Liquids, Gas
Element = Fundamental substance of matter
Groups of atoms of 1 type, e.g. Carbon, Oxygen, Hydrogen
Compund = Combination of 2 or more atoms, e.g. H 2O, C6H12O6
Molecule = 2 or more atoms chemically bonded together
 May either be an element or may be a compound
BULK ELEMENTS
Carbon (C)
Oxygen (O)
Hydrogen (H)
Nitrogen (N)
Magnesium (Mg)
Sulfur (S)
Sodium (Na)
Potassium (K)
Calcium (Ca)
Chlorine (Cl)
TRACE ELEMENTS
<0.1% OF ELEMENTS, BUT HAVE IMPORTANT
FUNCTIONS
Cobalt (Co)
Zinc (Zn)
Copper (Cu)
Iron (Fe)
Fluorine (F)
Mangenese (Mn)
Iodine (I)
ATOMIC STRUCTURE
Nucleus
 Protons
 Neutrons
Electrons – Orbit nucleus
Subatomic Particle
Atomic Weight (Daltons)
Charge
Proton
1
+1
Neutron
1
0
Electron
0
-1
 For most atoms, number of protons = number of electrons, and therefore are neutral
 Number of neutrons may vary
Atomic Number (AN) = Number of protons in an atom
 Defines the identity of an atom
 Changing the atomic number changes the atom
Atomic Weight (AW) = Number of protons + number of neutrons
Examples:
Hydrogen = 1proton, 1 electron, 0 neutrons
 Atomic Number = 1, Atomic Weight = 1
Helium = 2 protons, 2 electrons, 2 neutrons
 Atomic Number = 2, Atomic Weight = 4
Lithium = 3 Protons, 4 Neutrons, 3 Electrons
 Atomic Number = 3, Atomic Weight = 7
ISOTOPES
Isotopes
 Same atomic number, but different atomic mass
 Number of neutrons may vary
Example:
Isotope 1:
Isotope 2
Oxygen (O)
Oxygen (O)
8 protons
8 protons
8 electrons
8 electrons
8 neutrons
9 neutrons
Atomic Number: 8
8
Atomic Weight: 16
17
MOLECULAR FORMULA
 Shorthand of molecules
 Water = H2O……2 Hydrogen + 1 Oxygen Molecule
 Glucose = C6H12O6……6 Carbon + 12 Hydrogen + 6 Oxygen
BONDING ATOMS
Electron Orbit (Shell)
 Electrons orbit the nucleus in discrete orbits
 Inner orbit = holds 2 electrons
 2nd orbit = holds 8 electrons
 3rd orbit = holds 8 electrons
 Octet Rule
 Except for the 1st electron orbit, which holds 2 electrons, each additional orbit
holds 8 electrons
IONS
Ion = atom that gains or looses electrons
 Cation – Positively charged ion
 Anion – Negatively charged ion
 Example:
 Sodium (Na) = 11 protons, 12 neutrons, 11 electrons
 1 electron in outer orbit
 Outer lone electron is easily lost
 Na + = cation
 Chlorine (Cl) = 17 protons, 18 neutrons, 17 electrons
 7 electrons in outer orbit, which can hold 8 electrons
 1 electron is easily gained
 Cl- = anion
IONIC BOND
IONIC BOND
BONDS CONT.
Ionic Bond
 Oppositely charged ions attract and form a bond
 Ionic bonds form arrays such as crystals, but do not form molecules
Covalent Bond
 Atoms share electrons
 Hydrogen forms single bonds, H-H
 Carbon forms four bonds, Oxygen forms 2 bonds,
O=C=O
COVALENT BONDS
 NonPolar Covalent Bond
 Equal sharing of electrons, e.g. H2 (H-H)
 Polar Covalent Bond
 Unequal sharing of electrons, e.g. H2O (H-O-H)
 Oxygen has stronger attraction to electrons & is slightly – charged
 Hydrogen partially gives electrons to Oxygen & is + charged
HYDROGEN BOND
 Attraction of + hydrogen end to – Oxygen end
 Weak bonds at body temperature
 Forms crystals at lower temperatures, e.g. ice
CHEMICAL REACTIONS
1.
Synthesis
A + B → AB
2.
Decomposition
AB → A + B
3.
Exchange
AB + CD → AD + BC
4. Reversible
A + B ↔ AB
ELECTROLYTES
Electrolytes = release ions in water
e.g. NaCl → Na⁺ + Cl⁻
(ions dissociate in water)
2. Acids – electrolytes that release H⁺ (protons) in water
e.g. HCl → H⁺ + Cl⁻
3. Base – electrolytes that release OH⁻(hydroxide ions) in water
e.g. NaOH → Na⁺ + OH⁻
4. Acid + Base → Salt + Water
e.g. HCl + NaOH → NaCl + H2O
PH
 Neutral, pH = 7.0
 number of protons = number of hydroxide ions (H⁺ = OH⁻)
 e.g. Water H2O → H⁺ + OH⁻
 Acids, pH < 7.0
 Number of protons is greater than number of hydroxides (H⁺ > OH⁻)
 Bases, pH> 7.0
 Number of protons is less than number of hydroxides (H⁺ < OH⁻)
PH




average pH is 7.35-7.45
Acidosis = pH < 7.3
Alkalosis = pH > 7.5
Buffers = chemicals that resist changes in pH, stabilizes blood plasma pH levels
INORGANIC
Water (H2O)
 2/3 of weight in person
 Most metabolic reactions occur in water
 Transports gasses, nutrients, wastes, heat
Oxygen (O2)
Used to release energy from nutrients
Carbon Dioxide (CO2)
 waste byproduct of metabolic reactions in animals
Inorganic Salts
 Na⁺, Cl⁻, K⁺, Ca2⁺, HCO3⁻ (bicarbonate), PO42⁻ (Phosphate), ect.
 Role in metabolism, pH, bone development, muscle contractions, clot formation
CELLS
 Basic unit of life
 50-100 Trillion cells in human body
 Size and shape vary
 Size
 measured in micrometers (µm)
 1 µm = 1/1000mm
 Red Blood Cell = 7.5 µm
 Varieties
 260 types of cells in body, all from 1 fertilized egg
 Differentiation = forming specialized cells from unspecialized cells
 Cells include neurons, skeletal muscle, osteocytes (bones), red blood cells, ect.
CELL MEMBRANE
 Maintains integrity of cell
 Fluid membrane
 Flexible & elastic
 Selectively Permeable
 Allows only selective substances into and out of cell
 Permits communication between cell and environment
 Signal Transduction = cell interprets incoming messages
STRUCTURE
 Bilayer of phospholipids
 Phosphate “Head”
 Polar group
 Hydrophilic “water loving” = water soluble
 Fatty Acid Chains “tail”
 Nonpolar groups
 Hydrophobic “water fearing” = insoluble in water
 Oily
 Cholesterol
 Membrane Proteins
FORMATION OF MEMBRANE
 Phospholipids align in water
 Expose polar heads to water = polar outside
 Hide nonpolar tails from water = oily inside
 Nonpolar interior
 Allows nonpolar molecules to cross into and out of cell
e.g. O2,CO2, steroid hormones
Polar molecules cannot cross cell membrane
e.g. H2O, sugars, amino acids
Cholesterol
 Rigid steroid rings that add support to cell membrane
Membrane Proteins = Many types embedded in cell membrane
MEMBRANE PROTEINS
 Integral Proteins
 Spans across membrane
 Forms channels and pores
 e.g. aquaporins, Na+ channels
 Peripheral Proteins
 Project from outer surface
 May be glycoprotein (protein + sugar)
 Does not penetrate hydrophobic portion of membrane
 Usually attach to integral proteins
 Transmembrane Protein
 Spans from outside cell to inside cell
 Example 1 : Cellular Adhesion Molecules (CAM)
 CAMs bind cells to other cells, or to proteins
 May anchor cell, or communicate with other cells
 Example 2: Many receptors
 Transmits signals from extracellular environment into cell
NUCLEUS
 Nuclear Envelope
 Double layered membrane
 Nuclear Pores
 Channel proteins that allow specific molecules into and out of nucleus
 Messenger RNA leaves nucleus through pores
 Ribosomes leave nucleus through pores
 Nucleolus “little nucleus”
 Dense body of RNA & Proteins
 Produces ribosomes
 Chromatin “colored substance”
 DNA wrapped around proteins, called histones
 Tightly coil and condense during mitosis to form chromosomes “colored body”
MOVEMENTS
Passive = requires no energy from cell
Active = requires energy from cell in form of ATP
Passive Movements
 Diffusion
 Random movement of molecules from higher to lower concentration
 Molecules tend to diffuse = become evenly distributed
 Requirements:
 Cell membrane must be permeable to substance (small & nonpolar)
 e.g. CO2, O2, Steroids
 A concentration gradient must exist across membrane
 One side of cell membrane must have a greater concentration than the other
 Facilitated Diffusion
 Diffusion with the aid of a carrier protein
 Allows selective molecules to cross membrane
 e.g. ions, sugars, proteins, amino acids
 Carrier protein changes conformation
 Substances move down concentration gradient
 Limited by number of carrier protein
 Osmosis
 Diffusion of water across selectively permeable membrane
 Water passes through channels, called aquaporins
 Large solutes (salts) cannot cross membrane
 Water follows salts
 Osmotic pressure exerted on cell
 Isotonic = same solute concentration inside and outside cell
 Hypertonic = Greater solute concentration outside cell than inside cell
 Water leaves cell & cell shrinks
 Hypotonic = Greater solute concentration inside cell than outside
 Water enters cell and cell swells
 Cell may lyse “burst”
 Filtration
 Fluid is pushed across a membrane that larger molecules cannot cross
 Separates solids from liquids
 Force = hydrostatic pressure – derived from blood pressure
Active Transport
Movement against a concentration gradient
Requires ATP for energy (up to 40% of cell’s ATP)
Includes carrier proteins
e.g. Na+/K+ pumps can pump sodium out of cell and
potassium into cell
Establishes a concentration gradient
Endocytosis
 Cell membrane surrounds and engulfs particle
 Types include
 Pinocytosis
 Cell takes up a fluid
 Phagocytosis
 Cell takes up a solid
 Example: white blood cell engulfing a bacteria
 Receptor mediated endocytosis
 Selective endocytosis
 Receptors on cell membrane bind to substance and trigger
endocytosis
 Provides specificity
 Removes substances in low concentrations
Exocytosis
 Reverse of endocytosis
Transport substances out of cell
Vesicle merges with cell membrane and releases
content
Example- neuron releasing neurotransmitters
Transcytosis
 Endocytosis & Exocytosis
 Allows passage through a cell
 e.g. HIV enters body by transcytosis through epithelium of anus,
mouth, or reproductive tract.
Cell Cycle
Interphase
Mitosis
Cytokinesis = division of cytoplasm
Differentiation
INTERPHASE
G1 (Gap) Phase
 Cell is active and grows
 Growth followed by a checkpoint that determines cell’s fate.
 Cell May:
 Continue to grow, then divide
 Remain active, but not divide
 Die
S phase (S = synthesis)
 DNA replicates
G2 phase
 Cell prepares for cell division
MITOSIS
Mitosis occurs in somatic (non-sex) cells
Sex cells divide by meiosis
46 chromosomes –paired
23 paternal & 23 maternal
Chromatin condenses to become chromosome
Each replicated chromosome consists of 2 sister
chromatids
Chromatids held in place by centromeres
KNOW WHAT HAPPENS IN PMAT