Chapter 2: Chemistry Comes Alive

Transcription

1 Chapter 2: Chemistry Comes Alive Objectives: 1. Differentiate between matter and energy between potential energy and kinetic energy. 2. Describe the major energy forms. 3. Define chemical element and list the four elements that form the build of body matter. 4. Define atom. List the subatomic particles; describe their relative masses, changes and positions in the atoms. 5. Define atomic number, atomic mass, atomic weight, isotope and radioisotope. 6. Distinguish between a compound and a mixture. Define molecule. 7. Compare solutions, colloids and suspensions. 8. Explain the role of electrons in chemical bonding and in relation to the octet rule. 9. Differentiate among ionic, covalent, and hydrogen bonds. 10. Compare and contrast polar and nonpolar compounds. 11. Define the three major types of chemical reactions: synthesis, decomposition, and exchange. Comment on the nature of oxidation-reduction reactions and their importance. 12. Explain why chemical reactions in the body are often irreversible. 13. Describe factors that affect chemical reactions rates. 14. Explain the importance of water and salts to body homeostasis. 15. Define acid and base, and explain the concept of ph. 16. Describe and compare the building blocks, general structures, and biological functions of carbohydrates, lipids, proteins, and nucleic acids. 17. Explain the role of dehydration synthesis and hydrolysis in the formation and breakdown of organic molecules. 18. Describe the four levels of protein structure. 19. Describe the general mechanism of enzyme activity. 20. Describe the function of molecular chaperones. 21. Compare and contrast DNA and RNA. 22. Explain the role of ATP in cell metabolism. PART 1: BASIC CHEMISTRY Read (p ) and study the bold vocabulary words for a quiz next class. 1

2 Here are some IMPORTANT things that I did not want you to miss I. 4 elements make up 96% of your body weight A. Carbon B. Oxygen C. Hydrogen D. Nitrogen II. III. Chemical Bonds A. Bonds how atoms combine with one another by gaining or losing electrons; an attractive force between atoms B. Ionic Bond 1. Ions atoms that have lost or gained electrons a. anion a negatively charged ion b. cation a positively charged ion 2. An attraction between oppositely charged ions C. Covalent Bond 1. sharing of electrons between atoms D. Hydrogen Bonds 1. weak bond formed between hydrogen atoms (that are covalently bonded to another atom) 2. Examples: liquid water & DNA chains 3. easily broken and put back together Chemical Reactions A. Chemical Reaction occurs whenever chemical bonds are formed, rearranged or broken B. Chemical Equation 1. Reactants number and kinds of reacting substances 2. Products what occurs after the reaction C. Patterns of Chemical Reactions A. 3 types 1. Synthesis (Combination) Reaction a. atoms or molecules combine to form a larger, more complex molecule b. Energy A + B > AB H 2 0 2

3 c. bonds are formed d. endothermic reaction e. dehydration reaction f. anabolic activities 1. combining amino acids to make proteins 2. Decomposition Reaction a. molecule is broken down into smaller molecules b. H 2 0 AB > A + B Energy c. bonds are broken d. exothermic reaction e. hydrolysis reaction f. catabolic activities 1. glycogen molecules broken to release glucose 3. Exchange (Displacement) Reaction a. both synthesis and decomposition b. AB + CD AD + CB or AB + C AC + B c. bonds broken and formed 4. Oxidation Reduction Reactions (Redox) a. decomposition reaction 1. breakdown of food molecules b. exchange reaction 1. electrons (e - ) exchanged between reactants c. oxidized referrers to reactant losing the electron d. reduced referrers to the reactant gaining the electron e. Na + (oxidized) + Cl - (reduced) NaCl IV. Factors Influencing the Rate of Chemical Reactions 1. Temperature a. higher temperature faster reaction 2. Concentration a. higher concentration faster reaction 3. Particle Size a. smaller particles faster reaction 3

4 4. Catalyst a. substances that increase the rate of chemical reactions without being chemically changed b. biological catalyst enzyme PART II: BIOCHEMISTRY Biochemistry study of chemical composition and reactions of living matter Organic Compounds contain carbon (and hydrogen) Inorganic Compounds all other chemicals in the body I. Inorganic Compounds A. Water 1. High Heat Capacity a. absorbs and releases large amounts of heat b. prevents overheating by internal and external factors 2. High Heat of Vaporization a. requires a lot of heat to change from liquid to gas b. sweating removes a lot of heat from the body 3. Polar Solvent Properties a. Universal Solvent b. ionic compounds dissociate (break up) in water c. bodies major transport medium 4. Reactivity a. Hydrolysis reactions water added to split molecule b. Dehydration synthesis water removed to form bond 5. Cushioning a. forms cushion around organs to protect them B. Salts 1. An ionic compound containing cations (+) and anions (-) 2. When dissolved in water will dissociate 3. Electrolytes ions that dissociate in water and conduct electrical current 4. Very important to maintain proper ionic balance for body to work C. Acids and Bases 1. sour taste 2. substance that releases hydrogen ions (H + ) 3. when dissolved in water will release H + and anions 4

5 D. Bases 1. bitter taste and fell slippery 2. when dissolved in water will release hydroxyl ions (OH - ) E. ph: Acid-Base Concentration 1. ph scale = = acid = base F. Neutralization 1. when acids and bases react form water and salt G. Buffers 1. Chemicals that resist abrupt and large swings in the ph of body fluids 2. Release H + when ph rises and binds H + when ph falls 3. ph of blood a. ph < 7.4 = acidosis; lethal below 7.0; 1. Symptoms a. Disorientation b. Fatigue c. Breathing Difficulties 2. Causes a. Severe vomiting that empties the alkaline small intestine b. Diabetes c. Brain Damage d. Impaired Breathing e. Lung and Kidney Disease b. ph > 7.4 = alkalosis; lethal above Symptoms a. Feel agitated and dizzy 2. Causes a. Breathing rapidly at high altitudes b. Taking too many antacids c. High Fever d. Anxiety e. Mild to Moderate Vomiting that rids the body of stomach acids II. Organic Compounds A. Carbohydrates 1. sugars and starches 5

6 2. contain carbon, hydrogen and oxygen 3. Monosaccharide simple sugars a. ratio of Carbon, Hydrogen, Oxygen 1:2:1 b. important monosaccharides 1. glucose 2. deoxyribose 4. Disaccharides double sugar a. 2 monosaccharides joined by dehydration synthesis b. important disaccharides 1. sucrose (glucose + fructose) 2. lactose (glucose + galactose) 3. maltose (glucose + glucose) 5. Polysaccharide long chains of simple sugars a. Polymers chainlike molecules made of many similar units b. important polysaccharides 1. starch a. storage unit formed by plants 2. glycogen a. can t digest, but important part of bulk fiber 6. Carbohydrate Functions a. provide ready, easily used source of cellular fuel B. Lipids 1. insoluble in water but dissolve in other lipids and organic solvents (alcohol) 2. contain carbon, hydrogen and oxygen (oxygen very low) 3. Triglycerides a. fats when solid or oil when liquid b. building blocks 1. fatty acid 2. glycerol c. efficient and compact form of stored energy d. saturated fat fatty acid chain with single covalent bonds 1. solid at room temperature e. unsaturated fat contain one or more double bonds 1. liquid at room temperature 2. more heart healthy f. trans fats oils that have been solidified by addition of H atoms 1. increase risk of heart disease 6

7 g. omega-3 fatty acids decrease risk of heart disease 4. Phospholipids a. have hydrophilic head and hydrophobic tail b. very important in building cell membrane 5. Steroids a. fat molecules made of 4 interlocking hydrocarbon rings b. most important (?!?!?!) molecule cholesterol 1. found in cell membranes, vitamin D, steroid hormones, bile salts 2. steroid hormones sex hormones 6. Eicosanoids a. found in all cell membranes b. Prostaglandins 1. blood clotting, inflammation, labor contractions C. Proteins 1. basic structural material of body 2. contain carbon, oxygen, hydrogen and nitrogen 3. Amino Acids building blocks of proteins a. 20 amino acids b. how arranged determine what protein is made 4. Protein Denaturation a. Denatured when something causes protein to loose its shape or structures b. causes major malfunctions in the body 5. Enzyme and Enzyme activity a. proteins that act as biological catalysts b. cofactor ion of a metal or organic molecule that assists enzyme c. coenzyme a vitamin that assists enzyme d. examples of enzymes 1. hydrolases add water to break down molecules 2. oxidases add oxygen e. Activation Energy energy required to break bonds f. Substrate substance enzyme acts on 6. Functions of Proteins a. structure 1. keratin in hair, nails, skin b. transport 1. hemoglobin 7

8 c. chemical messengers 1. hormones 2. neurotransmitters d. movement 1. actin and myosin in muscle e. defense 1. antibodies f. catalysts 1. enzymes D. Nucleic Acids 1. carbon, oxygen, hydrogen, nitrogen, and phosphorus 2. Nucleotide structural unit of Nucleic Acid a. nitrogen-containing base b. pentose sugar c. phosphate group 3. Bases a. Adenine (A) b. Guanine (G) c. Cytosine (C) d. Thymine (T) e. Uracil (U) 4. Deoxyribonucleic Acid (DNA) 5. Ribonucleic Acid (RNA) E. ATP 1. Adenosine Triphosphate cell energy 2. Adenosine Diphosphate 3. when cell needs energy will turn ATP into ADP energy is lost when 3 rd phosphate is broken off 4. when cell stores energy will turn ADP into ATP energy is stored in bond of 3 rd phosphate 8