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Chemistry Of the Human Being Part 1: Organization of the Human Body Types of Chemistry Inorganic Chemistry: Deals with substances that aren’t based upon carbon molecules. Also known as General Chemistry Organic Chemistry: Deals with substances produced naturally by plants and animals and contain carbon. Organic Molecules Basis of human structure and function. 4 Primary Categories: Carbohydrates Lipids Proteins Nucleic Acid Chemical Elements Chemical Element: The simplest form of matter with its own unique chemical properties that cannot be broken down by ordinary chemical means. 112 known elements 92 occurring naturally Each element is made up of atoms (which are combinations of protons, neutrons, and electrons). Chemical Element Structures Central Nucleus Protons (+ charge) Neutrons (no charge) Ps & Ns in equal numbers Electrons: (- charge) Electron Shells 1st Shell: 2 Electrons 2nd Shell: 8 Electrons 3rd Shell & Beyond: 18 Electrons Periodic Table Information Atomic Number: The number of protons (same as neutrons). Atomic Mass: The number of protons plus the number of neutrons in the atom. Isotopes: Contain a different number of neutrons than protons. This doesn’t change the charge of the atom. Chemical Elements in the Human Body 24 elements important for human physiology 6 of these account of 98.5% of the human body’s total weight. Oxygen Carbon Hydrogen Nitrogen Calcium Phosphorus Ions Ion: Charged particle with unequal numbers of protons and electrons. Gains or loses electrons & develop an electronic charge. Cation: A particle that looses electrons and has a net positive charge. Ex. Na+ (sodium) Anion: A particle that gains an electron to develop a net negative charge. Ex. Cl- (chloride) Ions in the Human Body 4 Ions essential to human physiology Sodium: Na+ Chloride: CL Potassium: K+ Calcium: Ca++ Combinations Molecules: Chemical particles composed of two or more atoms. Atoms united by covalent bonding (sharing an electron pair). Atoms can be the same (O2) or different (CO2). Compounds: Composed of atoms of two or more different elements. Examples: Water (H2O), Sodium Chloride (NaCL) Free Radicals Charged groups of atoms with an odd number of electrons. Unstable and quick to combine with fats, proteins and DNA. Converts these into more free radicals which trigger chain reactions that destroy nearby molecules. Produced by… Some normal metabolic reactions of the body Radiation (including ultraviolet light and x-rays) Harmful chemicals (tetrachloride cleaning solvent) Antioxidants Antioxidants combat the chemical damage of free radicals by neutralizing their chemical reactions. Examples: Vitamin E, Selenium, Vitamin C Free Radicals have been linked to cancer, diabetes, arthritis, Alzheimer’s, and more. Bonding Bonds: How atoms are held together to form compounds and molecules. Chance of bonding depends on number of electrons in the valence (outer) shell. Atoms prefer to have 8 electrons in the valence shell. Octet Rule: Atoms that have 8 electrons in the valence shell are les likely to bond. 3 Basic Types of Bonds Ionic Bond: Relatively weak attraction between an Anion and Cation. Covalent Bond: Much stronger bond consisting of one or more shared electron pairs. Nonpolar Bond: Shares the electrons equally. Polar Bond: Shares the electrons uneqyally. Hydrogen Bond: A weak attraction between a hydrogen atom with a partial positive charge and a neighboring atom with a partial negative charge. Best example is water. Inorganic & Organic Compounds Inorganic Compounds: A compound that does not contain carbon. The most important compound (essential for life) is H20! Organic Compounds: A compound that contains carbon. Inorganic Compounds H20 is an important Inorganic compound due to it’s… Solvency: The ability to dissolve solutes (other chemicals). H20 known as a universal solvent because of its high number of dissolvable solutes. Cohesion: The tendency of molecules of the same substance to cling to each other. This causes the surface film of water known as surface tension. Inorganic Compounds H20 is an important Inorganic compound due to it’s… Chemical Reactivity: The ability of water to participate in a wide variety of chemical reactions. Hydrolysis reactions add water molecules to decompose compounds. Dehydration removes water molecules to add small molecules together. Thermal Stability: Water helps stabilize the internal temperature of the body. Water has a high heat capacity so can absorb or release large amounts of heat without changing its own temperature a whole lot. Organic Compounds Carbohydrates Monosaccharides Disaccharides Polysaccharides Triglycerides Fatty Acids Phospholypids Eicosanoid Steroids Proteins Carbohydrates Hydrophilic (water-loving) Organic (contain carbon) Main source of energy production for cellular chemical reactions ATP Typically have sacchar root word or ose as a suffix. Composed of 2:1 ratio of hydrogen to oxygen with carbon added in Monosaccharides Simple sugars composed of a single carbon containing molecule. Includes: Glucose (main blood sugar) Fructose (fruit) Galactose (milk) Disaccharides Simple sugars composed of 2 monosaccharide molecules. Includes: Sucrose (glucose + fructose; table sugar) Lactose (glucose + galactose; milk) Maltose (two glucose chains) Polysaccharides Complex sugars made of many monosaccharide molecules. Glycogen: Energy-storage polysaccharide in animals, stored in muscles and liver. Produced by the liver after a meal and when blood glucose is high. Liver breaks it down when blood glucose is low to maintain homeostasis. Polysaccharides Lipids: Organic, hydrophobic (won’t dissolve in polar solvents like water); composed of carbon, hydrogen, and oxygen. Function as a source of stored energy & components of cell structures. Much more variable in structure than other macromolecules. Primary function to store energy. Provide thermal insulation Act as a shock-absorbing cushion for organs 4 Primary Lipids in humans: Triglycerides, phospholipids, eicosanoids, & steroids. Lipids Important to the Human Body Triglycerides: Most common lipid in the body & the diet; stored as adipose tissue. Consists of 3 fatty acids attached to glycerol. Fatty Acids: Saturated: Full of hydrogen with a single bond between carbon atoms; sold at room temperature. Unsaturated: Room for hydrogen with double bonds between carbon atoms; liquid at room temperature Polyunsaturated: More than one double covalent bond between carbon atoms. Monounsaturated: One double bond between atoms. Nonessential Fatty Acids: Can be synthesized by the human body Essential Fatty Acids: Must be obtained from the diet. Lipids Important to the Human Body Phospholipids: Any lipid containing phosphorus, including those with a backbone (base) or glycerol or sphingosine. The major lipid in cell membranes. Eicosanoids: Any physiologically active substance derived from arachidonic acid. Includes Eprostaglandins. Along with prostaglandins, plays an important role in inflammation, blood clotting, hormone action, labor contractions, and control of blood pressure. Lipids Important to the Human Body Steroids: Lipids composed of 4 rings of carbon atoms and include cholesterol. Cholesterol is necessary for human life & is a building block molecule for all sex hormones, adrenalin, and is an essential cell membrane component. Proteins Proteins: “Proteios” is Greek for “of first importance.” Most versatile molecules in the body Structural component of cells and tissue Are polymers (large molecules) of building blocks called amino acids joined by peptide bonds. Composed of carbon, hydrogen, oxygen, nitrogen Proteins have complex coiled and folded structures critically important to their function. Even slight changes can destroy or change protein function. Proteins 4 Basic structural Formations: Primary: Sequence of amino acids in polypeptide chain (10-2000 amino acids joined together) Secondary: Two neighboring polypeptide chains held together by hydrogen bonds. Tertiary: 3-dimensional shape of a polypeptide chain Quaternary: Arrangement of 2 or more polypeptide chains in relation to each other. Proteins Proteins have more diverse functions than other macromolecules, including… Structural: Keratin, elastin, and collagen provide structural support Regulatory: Many hormones and neurotransmitters regulate important body functions Catalysis: Most metabolic pathways of the body are controlled by enzymes that function as catalysts Immunity: I.e., antibodies Contractile: Allow muscle to shorten and produce movement (actin & myosin) Mixtures Mixtures: Consists of substances that are physically blended together but NOT chemically combined. The chemicals mixed retain their own chemical properties. Can be Solutions, Colloids, or Suspensions Characteristics of Solutions Dissolved solutes Mixed with an abundant solvent (such as water) Solvent is transparent Small particle size Solute evenly dispersed within solvent Characteristics of Colloids Mixture typically cloudy (opaque) Particles less than 100 nm Particles suspended but not dissolved Particles typically small enough to remain permanently mixed with the solvent so they don’t settle Most common colloid in the body is protein Examples albumin in blood Milk is a colloid due to large proteins Characteristics of Suspension Suspended particles larger than 100 nm Particle size causes suspension to be cloudy Particles too heavy to remain permanently suspended (will separate on standing) Example: Blood is a suspension of plasma and blood cells Acids & Bases: pH pH scale: Ranges from 0 to 14 Denotes the level of Hydrogen ions (H+) & Hydroxide ions (OH-) in a solution. An equal number of H+ and OH- particles is a neutral pH level of “7”. Acidic: More H+ than OH- (pH less than 7) Alkaline: More OH- than H+ (pH more than 7) pH in the Human Body Blood has a normal pH of 7.35 to 7.45 Acidosis: pH below 7.35 Alkalosis: pH above 7.45 Work & Energy Energy & Work are the process of breaking old bonds (releasing energy) and forming new bonds (requiring energy). All activities by the body require energy! Four main types of energy are… Potential energy Kinetic Energy Chemical Energy Activation Energy Potential Energy Potential energy: Energy stored by matter because of its position or internal state. Is NOT doing work at this point in time. Kinetic Energy Kinetic energy: Energy of motion. Example: Heat! Heat occurs because of molecular activity/motion. The more activity/motion occurs, the more heat is generated. Chemical Energy Chemical Energy: Potential energy stored in the chemical bonds of molecules. Found in all molecules sharing a bond. Activation Energy Activation Energy: The amount of energy needed to allow an atom or molecule to collide with another and cause a disturbance of their valence electrons. Is influenced by amount of particles and the environmental temperature. The more particles & the higher the temperature, the more likely a collision & resulting chemical reaction is. Activation Energy The amount of particles in the body and the normal temperature are not high enough to trigger a life-sustaining rate of chemical reactions. Catalysts: Substances that speed up the rate of chemical reactions in the body by lowering the amount of activation energy needed to start the reactions. Do not alter the reactants or the products of the chemical reaction. Enzymes used as a catalyst in the human body. Enzymes Enzymes: Function as biological catalysts to permit the biochemical reactions to occur rapidly at normal temperatures. Substrate: A reactant molecule onto which the enzyme acts; each enzyme only binds to a specific substrate. Active Site: Part of the enzyme that catalyzes the reaction, Apoenzyme: Protein portion of an enzyme. Cofactor: Nonprotein portion of an enzyme. Metabolism Metabolism: The sum of all chemical reactions in the body. Has 2 divisions: Anabolism: Energy requiring reactions where small molecules are bonded to form larger ones. AKA Synthesis or Endergonic Reactions Catabolism: Energy releasing reactions where large molecules are broken down into smaller ones. AKA Decomposition or Exergonic Reactions Adenosine Triphosphate (ATP) The body’s most important energy-transfer molecule! Much of the energy used to synthesize ATP comes from glucose oxidation. First stage of glucose oxidation is glycolysis (meaning “sugar splitting”) Glycolysis 1. Glucose split into 2 Pyruvic acid molecules 1. 2. If oxygen is not available than anaerobic metabolism takes place (fermentation) 1. 2. 3. Produces lactic acid (toxic end product responsible for muscle soreness & converted back to pyruvic acid by the liver) Enables glycolysis to continue without oxygen If oxygen is available, than aerobic metabolism takes place 1. 2. 2 molecules of ATP produced, but most energy retained in the pyruvic acid Break pyruvic acid down into Carbon dioxide (CO2) and water (H2O) Generates a total of 38 ATP Glycolysis Anamation Nucleic Acid Nucleic Acid: polymers of nucleotides or chains of repeating monomers HUGE organic molecules containing carbon, hydrogen, oxygen, nitrogen, and phosphorous. Includes… Deoxyribonucleic Acid (DNA) Ribonucleic Acid (RNA) DNA Largest nucleic acid is Deoxyribonucleic acid (DNA) that constitutes the human genome (genes) Provides genetic code (instructions) for the manufacture of all proteins Transfers genetic information from cell to cell when cell division take place & from generation to generation in reproduction Composed of a double-stranded helix containing 4 nitrogenous bases in set pairs: Adenine (A) bonds to Guanine (G) in larger double-ring bases known as purines. Thymine (T) bonds to Cytosine (C) in smaller single-ring bases known as pyramidines. RNA RNA translates the genetic information from DNA into specific proteins. Single-stranded molecules