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The Chemistry of Life 1. List the major chemical elements of the human body. (pp. 56) a. Element: simplest form of matter to have unique chemical properties, i.e. hydrogen/oxygen = water • Has protons, neutrons, electrons • Atomic number: number of protons in its nucleus • Represented by one or two letter symbols b. Naturally occurring elements on earth (table 2.1) • Major Elements: Six account for 98.5% of body’s weight: oxygen, carbon, hydrogen, nitrogen calcium and phosphorus • Lesser Elements:0.8% consists of 6 elements: sulfur, potassium, sodium, chlorine, magnesium and iron • Trace elements: remaining 12 elements accounting for 0.7% of body weight • Minerals: inorganic elements that are extracted from the soil by plants and passed up the food chain to humans & other organisms—consist of 4% of human body weight, Ca, P, Cl, Mg, K, Na and S 1. Contribute to body structure, bones, teeth; enable enzymes to function (i.e. iodine component of thyroid hormone, iron component of hemoglobin)

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2. Define ion, electrolyte and free radical. (pp 59-60) Ions: • Charged particles with unequal numbers of protons and electrons. • Elements with one to three valence electrons tend to give them up; 4-7 electrons tend to gain more • Ionization: If an atom of the first kind is exposed to an atom of the second, electrons may transfer from one to the other and turn both of them into ions (Figure 2.4) Anion: particle that gains electrons acquires a negative charge Cation: one the lose electrons acquires a positive charge due to a surplus of protons. Electrolyte: Salts that ionize in water and form solutions capable of conducting electricity (Table 2.2) Important for their chemical reactivity (calcium phosphatebone), osmotic effects(influence water content) and electrical effects (nerve and muscle function) Free Radicals: Chemical particles with an odd number of electrons produced by some normal metabolic reactions of the body (WBCs trying to kill bacteria); radiation (UV radiation); chemicals (cleaning solvents, preservatives) Short-lived, combine quickly with molecules such as fats, proteins and DNA, converting them into free radical and triggering chain reactions cancer, myocardial infarction. Antioxidants: chemical that neutralizes free radicals.; dietary deficiencies of antioxidants increase in heart attacks, sterility, muscular dystrophy and other disorders

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3. Define the types of chemical bonds. (pp. 61-63) Table 2.3 a. Molecules: chemicals composed of 2+ atoms united by a covalent chemical bond (sharing of electrons) b. Compounds: molecules composed of two or more different elements (i. e. Carbon Dioxide) c. Organic compounds: all contain carbon atoms. Carbohydrates (energy sources). Lipids (fats important in cell membranes and long term energy storage). Proteins ( components of bones, muscles, nerves and other bodily structures) Nucleic acids (DNA-genetic memory; RNA—produce proteins) ATP: excellent sources of energy d. Chemical Bonds: molecules attracted to and held together i. Ionic: Cation + Anion; weak, and easily break up in the presence of water (i.e. NaCl breaks down as salt dissolves in water, Na+ and Cl- are attracted to water molecules) ii.Covalent: sharing of electron (Figure 2.6) iii.Hydrogen: weak attraction between a slightly positive hydrogen atom in one molecule and a slightly negative oxygen or nitrogen atom in another 4. Define acid, base and pH. (p. 67) a. Acid: proton donor, a molecule that releases a proton (H+) in water (pH = 0.0-7) b. Base (alkaline): proton acceptor of H+ (pH = 7.1-14) c. Water: neutral: pH = 7.0 Inorganic compounds: acids, bases, salt, water, carbon dioxide and oxygen 5. Describe the pH scale. (p. 67), figure 2.12 • mole: gram molecular weight • Molarity: number of moles of solute per liter of solution. • pH: measure derived from the molarity of H+. Molarityof H+ increase as acidity increases. Slight disturbances of pH can seriously disrupt physiological functions and alter drug actions. I.e. Blood pH 7.35-7.45, if not  tremors, fainting, paralysis or death) • Buffers: chemical solutions that resist changes in pH (chapter 24 Water, Electrolyte and Acid-Base balance)

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6. List and define the fundamental types of chemical reactions. (pp. 69-70), figure 2.13 a. Chemical Reaction: process in which a covalent or ionic bond is formed or broken. i. Decomposition reactions: large molecule breaks down into two or more smaller ones (Fig 2.13a) Starch molecule glucose molecules ii.Synthesis reactions: two or more small molecules combine to form a larger one, combine several hundreds amino acids into one protein molecule iii.Exchange reactions: two molecules exchange atoms or groups of atoms. AB+CDAC+BD (fig. 2.13c) Stomach Acid (HCl) enters Small intestinepancreas secretes sodium bicarbonate to neutralize it; sodium has exchange is bicarbonate group for a chlorine atom. iv.Reversible reactions: can go in either direction under different circumstances and are represented with double-headed arrows. Direction determined by relative abundance of substances on each side of t equations. If surplus of Carbon Dioxide, the will shift reaction to produce bicarbonate and hydrogen ions, if opposite is thru then reaction proceeds other way to generate CO2 and H20. Exist in state of equilibrium in which the ration of product to reactant is stable. 7.

Describe the factors that govern the speed and direction of a reaction. (p.70) Basis for chemical reactions is molecular motion and collisions; always in constant motion, reactions occur when mutually reactive molecules collide with sufficient force and the right orientation. a. Concentration: increase when reactants are more concentrated, due to molecules are more crowded and collide more frequently. b. Temperature: increase as temperature rise, molecules move faster c. Catalysts: substances that temporarily bind to reactant, hold them in favorable position to react with each other, speeds up the reaction, It releases the products and is available to repeat process (enzymes)

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8. Describe metabolism and its two divisions, anabolism and catabolism. (p.70-71), Table 2.5 Metabolism: catabolism + anabolism Catabolism: energy-releasing decomposition reaction. Breaks covalent bonds, produce smaller molecules from larger ones release energy that can be used for other physiological work (exergonic reactions) Anabolism: energy storing synthesis reaction, production of protein or fats reactions that require energy input (endergonic reactions) driven by energy that catabolism releases ( endergonic and exergonic processes linked) Oxidation: Chemical reaction when molecule gives up electrons and releases energy. Whatever molecule takes the electrons from it is an oxidizing agent (electron acceptor) ;oxygen is often the electron acceptor. Reduction: chemical reaction when molecule gains electron and energy. When a molecule accepts electrons it is said to be reduce. Reducing agent (electron donor) oxidation of one molecule is always accompanied by reduction of another. electrontransfer: oxidation-reduction reactions

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9. Discuss the relevance of polymers to biology. (p. 72, fig. 2.15) Polymer: molecules made of a repetitive series of identical or similar subunits called monomers. I.e. starch is 3,00o glucose monomers. Polymerization: joining of monomers. Dehydration synthesis (condensation): Polymerization take place by this process. a. -OH (hydroxyl) group is removed from one monomer and a hydrogen (-H) fro another, producing water as a by product. b. The two monomers become joined by a covalent bond, forming a c. Process is repeated for each monomer added to the chain, leading to a polymer chain Hydrolysis: opposite of dehydration synthesis; digestion consists of these reactions. a. Water molecule ionized into OH- and H+. b. Covalent bond liking one monomer to another is broken, the OH-is added to one monomer c. H+ is added to the other one

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10. Identify the types and functions of carbohydrates Table 2.6, pp. 72-74) Carbohydrate: hydrophilic organic molecule with ratio of 2:1 ratio of hydrogen to oxygen. Usually root word sacchar- or suffix -ose. sugars and starches Monosaccharides: simple sugars obtained by body by digestion of complex carbohydrates. Source of energy that can be quickly mobilized. Digested carbohydrate --> glucose --> oxidized--> ATP (energy compound) Types: glucose (blood sugar), provides us with the most energy; fructose; galactose Ribose/deoxyribose: components of DNA and RNA Disaccharides: sugars composed two monosaccharides Sucrose = glucose + Fructose (from sugarcane/sugar beets--table sugar) Lactose = glucose + galactose (milk sugar) Maltose = glucose + glucose (starch digestion, found in germinating wheat and malt beverages) Polysaccharides: long chains of glucose Glycogen: energy-storage polysaccharides made by cells of liver (after a meal, blood glucose level is high, liver breaks it down to maintain stores of energy, muscles (stores it for own energy needs), uterus and vagina (uses it to nourish the embryo) Starch: energy-storage polysaccharide of plants. Store it when sunlight and nutrients are available and use it when photosynthesis is not possible (night and winter) Cellulose: structural polysaccharide that gives strength to cell walls of plants. principalcomponent of wood, cotton, paper. common component in our diets, we have no enzyme to digest it; receive no energy or nutrition from it--> dietary fiber, bulk roughage. sells with water in digestive tract and helps move other material through the intestine. Glycolipids and glycoproteins--conjugated or covalently bonded with lipids/proteins with carbohydrates

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11. Identify the types and functions of lipids, pp. 75-78 Table 2.7) Hydrophobic organic molecule composed of carbon, hydrogen and oxygen, high ration of hydrogen to oxygen.,less oxidized than carbohydrates, have more calories per gram. Primary function: energy storage. If concentrated in adipose tissue--thermal insulation and shock absorption for vital organs. • Fatty acid: chain of 4-24 carbon atoms with a carboxyl group at one end and methyl group at the other. Saturated fat (animal fat, solid at room temperature): Saturated with hydrogen. Unsaturated fat: carbon atoms joined by double covalent bonds. Share electrons with hydrogen atom • Polyunsaturated: C=C bonds, most can be synthesized by the human body. Essential fatty acids must be obtained from diet • Triglyceride (neutral fats): liquid at room temperature. Polyunsaturated-- Plant triglycerides (peanut, olive, corn) molecule of 3 fatty acids covalently bonded to 3 carbon alcohol (glycerol) once joined to glycerol, fatty acid can no longer donate a proton to solution and no longer an acid. Broken down by hydrolysis reaction, split each of bond apart by addition of water. Phospholipids (Figure 2.20): similar to neutral fats, have a phosphate group. AmphiphilicDual nature: have 1 head (phosphate--hydrophilic) and 2 tails (fatty acids--hydrophobic): Clothespin shape. form the structural foundation of cell membranes Eicosanioids: 20 carbon compounds derived from arachidonic. function as chemical signal between cells. Signals inflammation, blood clotting, hormone action, labor contraction control of blood vessel diameter (Endocrine System, Chapter 17) Steroid: 17 carbon atoms arranged in 4 rings. Cholesterol--parent steroid--> other steroids synthesized from this (only occurs in animals) important component of cell membranes, required for proper nervous system functions.

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12. Discuss protein structure and function (pp. 79-82) “proteios-- of first importance” Amphiphilic (hydrophilic and hydrophobic) Amino Acids--polymer of amino acid Peptide: any molecule composed of 2+ amino acids joined by peptide bond peptidebond: formed by dehydration synthesis, joins amino group to one amino acid to carboxyl group of the next. named for number amino acids they have dipeptides have 2 etc. Protein Structure (Fig. 2.24): complex coiled and folded structure Changes in their conformation (3D shape) can destroy protein function •

Primary structure: proteins sequence of amino acids, encoded in genes (chapter 4) • Secondary structure: coiled or folded shape held together by hydrogen bonds between slightly negative C=O group of one peptide bond and slightly positive N-H group of another peptide bond ad distance away. Spring-like shape called a helix, ribbon-like, pleated, could also be pleated sheet shape • Tertiary structure: formed by further bending and folding of proteins in to various globular and fibrous shapes. Resulting from hydrophobic R groups associating with each other and avoid water while the hydrophilic R groups are attracted to surrounding water. Globular proteins (wadded ball of yarn) suited for proteins embedded in cell membranes and protein that must move freely in body fluid (enzymes and antibodies). Gives proteins (myosin, keratin, collagen) slender filaments --for muscle contractions and providing strength to skin, hair and tendons. • Quaternary: association of 2+ polypeptides chains by non-covalent forces such as ionic bonds and hydrophilic=hyphobicinteractions. Occurs only in proteins. * ability to change conformation, triggered by voltage changes on cell membrane during action of nerve cells, binding of a hormone to a protein and dissociation of a molecule from a protein Reversible changes important to enzyme function, muscle contraction, opening and closing of pores in cell membranes. Conjugated proteins--non-amino acid moiety--prosthetic group covalently bound to them. I.e. hemoglobin cannot transport oxygen unless iron contain ring is attached

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PROTEIN FUNCTIONS: Structure: keratin for nails, hair and skin surface, collagen-deeper layer of skin, bone, cartilage and teeth. Communication: hormone and cell-to-cell signal, receptors for signal molecule bind in receiving cell. Membrane transport: form channels in cell membranes to govern what and when things can pass in and out of cells. Switch to turn on/off nerve and muscle activity. Catalyst: metabolic pathways are controlled by enzymes, globular proteins function as catalyst. Recognition and protection: immune recognition. Attract and neutralize organism that invade the body. Clotting protein protect the body against blood loss Movement: because able to change shape repeatedly are basis for movement. Cell adhesion: bind cells to each other. Enable sperm to fertilize eggs, immune cells to bind to cancer cell and keep tissues from falling apart. 13. Explain how enzymes function. (Fig. 2.26) Enzymes:proteins that function as biological catalyst. Energy needed to get reaction started--activation energy. • permit biochemical reactions to occur rapidly at normal body temp. • pepsin, trypsin, substrates (such as amylase which digests starch). carbonic anhydrase removes water from carbonic acid. • oxidizeglucose to water and carbon dioxide to extract it s energy. enzymes lower the activation energy, reducing the barrier to glucose oxidation by releasing the energy in small steps rather than singe burst of heat. Enzyme substrate complex: (figure 2.27) a. Substratebind to active sites in enzyme surface. b. Enzyme breaks down covalent bonds and converts the substrate to a ratio product or hold substrates close together (so the substrate react with each other). c. Once released, the reaction-products free to do process again and are not consumed by reaction. They catalyze again and again at fast speed. d. Enzyme substrate specificity: an enzyme for glucose will only act on glucose. e. Temperature and pH destroy ability of enzyme to bind its substrate., disrupts hydrogen bonds and change the lock so key no longer fits. pH varies according to where they function. but always at 37 degrees Celsius. Co-Enzyme: enzymes cannot function without non-protein partners called cofactors. (iron, zinc, magnesium, calcium ions). By binding to an enzyme, a cofactor may stimulate it to fold into a shape that activates its active site. Co-Enzymes: organic co-factors, derived from niacin, riboflavin, and other Page 9 of 10

water soluble vitamins. They accept electrons from an enzyme in one metabolic pathway--transfer them to enzyme in another pathway. (fig 2.28) 14. Describe the structure and function of ATP. (pp. 86-87) Adenosine triphosphate: ATP: body’s most important energy-transfer molecule, briefly stores energy gained from exergonic reactions such as glucose oxidation and releases it within seconds for physiological work such as polymerization reaction, muscle contraction and pumping ions through cell membranes Enzyme called adenosine triphosphatases hydrolyze the third high energy phosphate bond to produce ADP Short lived molecule consumed within in 60 seconds of formation.. It is lethal because it halts ATP synthesis. (Chapter 26). (muscle physiology chapter 11). ATP synthesis come from glucose oxidation (fig. 2.30) Glycolysis (sugar splitting) fig. 2.31-- split the 6 carbon glucose molecule into 2 three carbon molecule of pyruvic acid. little ATP is produced (2 ATPs: glucose) Anaerobic respiration: If oxygen not available pyruvic acid converted to lactic acid by a anaerobic fermentation; does not extract any more energy from pyruvic acid. Lactic acid it produces is toxic. Advantage: enable glycolyis to continue and enable cell to continue producing a small amount of ATP Aerobic respiration: When oxygen available, more efficient. Pyruvicacid is broken down to carbon dioxide and water and generates up to 36 more molecules of ATP to original glucose molecule. Reactions of aerobic respiration are carried out in cell’s mitochondria. 15. Identify types of nucleic acids. polymers of nucleotides DNA: 100 million to 1 billion nucleotides long, constitute our genes, give instructions for synthesizing all the body’s proteins and transfers hereditary information from the cell to cell when cells divide and from generation to generation when organism reproduce. Three forms of RNA carry out those instructions synthesize the proteins assembling amino acids in the right order to produce each protein described by the DNA (Chapter 4)

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