<p> Unit II Study Guide KEY</p><p>1. Polarity = Unequal sharing of electrons in a covalent bond due to strong electronegativity (“buffness”) of one atom</p><p>2. cohesion, adhesion Allows water to move up from roots to leaves 3. Heat is absorbed, released when hydrogen bonds break, form; allows water to be relatively unaffected by temperature change 4. High heat of vaporization Cooling effect of perspiration 5. Hydrogen bonds in solid ice hold water molecules further apart; less dense as solid Protects aquatic life, insulates 6. Universal solvent Polar water molecules “pull apart” other polar, ionic substances 7. Coffee 8. Orange juice has 100X more H+ than coffee 9. 10 -3 3 acid 10. 10 -6 8 base 11. 10 -1 10 -13 acid 12. 10 -7 7 neutral + – 13. a. H2CO3 ↔ H + HCO3 b. To the right; [H+ ] will increase to decrease pH c. 7.4 14. Dehydration synthesis 15. Hydrolysis 16. Dehydration synthesis 17. Dehydration synthesis 18. Hydrolysis 19. Dehydration synthesis 20. a. Hydroxyl – polarity b. Aldehyde – polarity c. Ketone – polarity d. Carboxyl – acts as an acid by donating H+ e. Amino – acts as a base by removing H+ 21. a. Aldehyde – polarity; hydroxyl – polarity; phosphate – negative charge b. Methyl – non-polar, hydrophobic c. Hydroxyl – polarity; ketone – polarity; phosphate – negative charge d. Aldehyde – polarity; hydroxyl - polarity e. Sulfhydryl – ability to form disulfide bridges with other sulfhydryl groups; amino – acts as a base; carboxyl – acts as an acid f. Methyl – non-polar, hydrophobic 22. a. Carb; mono b. Carb; poly c. Lipid; saturated fat d. Nucleotide e. Nucleic acid f. Lipid; saturated fatty acid 23. a. b. lactose c. glucose and galactose d. hydrolysis e. Induced fit refers to the slight “hug” that occurs when the substrate fits into the active site. This is important because it either stresses the bonds slight to allow for break down, or holds substrates closely together to facilitate bonding f. Competitive inhibitor – takes up active site, physically blocking substrate; non-competitve inhibitor – changes shape of active site by binding with enzyme at another location g. Regulation of enzyme activity in which protein’s function at one site is affected by the binding of a regulatory molecule at another site; activator “turns on” enzyme; inhibitor “turns off” enzyme 24. a. Non-polar b. Basic c. Polar d. Polar e. Basic 25. Secondary 26. Quaternary 27. Primary 28. Secondary 29. Tertiary 30. Secondary 31. Structural = cellulose – cell walls of plant cells; chitin – cell walls of fungal cells; insect exoskeleton; peptidoglycan – cell walls of Eubacteria 32. Storage = glycogen – animals; starch – plants; Both polymers of glucose 33. a. Sucrose or lactose or maltose b. Disaccharide c. Sucrose or lactose or maltose d. sucrose = glu + fru; lactose = glu + galac; maltose = glu + glu e. dehydration synthesis 34. Not true polymers; all non-polar, hydrophobic; CHO but very Os a. Fats & oils – energy storage, insulation & cushioning in animals b. Phospholipids – primary component of all cell membranes c. Steroids – cholesterol  Hormones  Found in animal cell membranes to maintain stability, fluidity 35.  Saturated fats contain all single bonds; fully saturated with hydrogens; solid at room temp due to closely-packed fatty acid tails; greater health risk  Unsaturated fats contain at least one double bond; produces “kink” in fatty acid chains that maintain fluidity at room temp; typically plant source 36. a. phosphate group b. deoxyribose c. nucleotide d. adenine – purine e. guanine – purine f. thymine – pyrimidine g. cytosine – pyrimidine  DNA is a double helix; RNA is a single helix.  The sugar in DNA is deoxyribose; ribose is found in RNA  In RNA, uracil replaces thymine. </p>