Biology 12 - Biochemistry Practice Exam KEY Water: 1. The bond between water molecules is a(n) a. ionic bond b. covalent bond c. polar covalent bond d. hydrogen bond 2. The water properties: good solvent, temperature regulator and lubricant all depend on a. ionic bond b. covalent bonds c. peptide bonds d. hydrogen bonds 3. The weakest bond below is a. hydrogen bond b. peptide bond c. covalent bond d. ionic bond 4. List 3 special properties of water. Good temperature regulator ex. sweat Good lubricant - in joints of body Good solvent - dissolves substances ex. blood Acids, Bases and buffers: 5. Which of the following would be produced during exercise and cause the ph of the body to drop? a. K b. Cl - c. C a d. H + 6. A solution becomes more acidic when a chemical is added to it. The chemical added contains a. sodium ions b. hydrogen ions c. hydroxide ions d. bicarbonate ions 7. What number below represents a strong acid on the ph scale? a. 8 b. 10 c. 3 d. 6 8. The purpose of buffers is to a. increase ph b. neutralize solution c. absorb all the OH ions d. control ph level 9. A slightly basic solution has a ph value of a. 9 b. 6 c. 8 d. 3 10. High basicity depends on a. high OH - ion conc. b. high H + ion conc. c. low dissociation level d. polar bond formation 11. A slightly acid solution has a ph value of a. 9 b. 6 c. 8 d. 3 12. High acidity depends on a. high OH - ion conc. b. high H + ion conc. c. low dissociation level d. polar bond formation 13. Buffers a. keep ph at 4 b. keep ph neutral c. keep ph at 7.4 d. remove excess H + and OH - ions 14. When hydrogen chloride, a strong acid, is added to water, the ph a. goes up b. stays the same c. goes down d. cannot be determined 15. Acids have a ph that is less than 7, and bases have a ph that is greater than 7. 16. At ph = 7, [ H + ] = [ OH - ]. Below ph 7, which of these is greater? [ H + ]
17. Which of the following represents the largest [ H + ] ph = 3, ph = 4, ph = 8, ph = 10 18. Define: acid and base acid - increase [ H + ], ph less than 7 base - increase [ OH - ], ph greater than 7 19. What is the importance of ph to biological systems? Extremes in ph cause proteins to denature, they lose their normal shape and may not function. Carbohydrates: 20. Maltose is an example of a a. monosaccharide b. disaccharide c. polysaccharide d. protein 21. Starch, cellulose and glycogen are all a. lipids b. monosaccharides c. polysaccharides d. disaccharides 22. In carbohydrates the ratio of hydrogen to oxygen is usually a. 6 : 12 b. 2 : 1 c. 1 : 2 d. 3 : 1 23. Which of the following is not a carbohydrate? a. fructose b. glucose c. amino acid d. starch 24. When many glucose molecules undergo dehydration synthesis, the result is a. protein b. phospholipid c. polysaccharide d. polypeptide 25. Glucose is an example of a(n) a. monosaccharide b. disaccharide c. polysaccharide d. protein 26. Which of the following is not stored in animal tissues? a. lipids b. protein c. glycogen d. starch 27. Which of the following is not found in plant tissue? a. lipids b. starch c. glycogen d. cellulose 28. Which pair is mismatched? a. amino acid - protein b. fatty acid - glycogen c. glucose - starch d. phosphate - nucleotide 29. Monosaccharides, disaccharides and polysaccharides may be compared as to the number of monosaccharide (or glucose) molecules they contain. 30. Which of the following represents the building blocks of carbohydrates? B
Proteins: 31. Proteins are polymers of a. nucleotides b. amino acids c. fatty acids d. monosaccharides 32. The groups H - N - H and O = C - OH are both found in a. lipids b. polysaccharides c. amino acids d. monosaccharides 33. A peptide bond a. joins fatty acids b. joins monosaccharide sugars c. joins disaccharide sugars d. joins amino acids 34. A chain of two amino acids is called a a. dipeptide b. diphosphate c. dinucleotide d. disaccharide 35. A peptide bond joins a. C with O b. C with N c. C with C d. O with H 36. Different kinds of amino acids are usually distinguished by the a. number of carbon atoms present b. the R groups present c. how many amino acids are missing d. whether or not Nitrogen is present 37. The backbone of a polypeptide would be composed of a. the bases b. sugar-phosphate-sugar-phosphate c. N - C - C - N - C - C etc. d. the R groups 38. Which of the following contains the element Nitrogen? a. fructose b. glucose c. amino acid d. starch 39. A single helix shape of a protein would be described as a a. primary protein b. secondary protein c. tertiary protein d. globular protein 40. The primary structure of a protein is a polymer of amino acids, A secondary structures shape can described as bent, and the tertiary structures shape can be described as bent and folded A quaternary structure contains more than 1 polypeptide. 41. Draw and label an amino acid: include functional group, amine group, carboxyl acid. 42. Describe what makes each amino acid different. R or functional group 43. Define denaturation. The change in shape of a protein 44. State 3 ways that protein may be denatured. Extremes in ph, extremes temperature, heavy metals
45. Why is denaturation of protein a problem for organisms? Proteins lose their shape and may not function 46. List 4 functions of proteins. Structural, enzymes, hormones, antibodies, hemoglobin, muscle 47. Which of the following represents the building blocks of proteins? A Lipids: 48. Fats, phospholipids and steroids are all a. proteins b. carbohydrates c. lipids d. steroids 49. Which of the following would be considered a polymer? a. glucose b. neutral fat molecule c. unsaturated fatty acid d. saturated fatty acid 50. A neutral fat is composed of 3 a. glycogen b. glucose c. phospholipids d. fatty acids 51. Which molecule is unsaturated? B 52. Double bonds between the carbons indicates a (n) a. saturated fatty acid b. unsaturated fatty acid c. neutral fat d. phospholipid 53. An unsaturated fatty acid contains less HYDROGEN than a saturated one. 54. Describe the function of the 3 following lipids. Neutral fat - long term energy storage, insulation, cushioning Phospholids - form cell membranes Steroids - hormones and cholesterol
55. Which of the following types of fatty acids might be considered Brain food? a. trans fatty acids b. omega 6 fatty acids c. omega 3 fatty acids d. cis fatty acids 56. Which of the following fatty acids is produced during food processing and can lead to such things as cardiovascular disease and cancer? a. trans fatty acids b. omega 6 fatty acids c. omega 3 fatty acids d. cis fatty acids Nucleic acids: 57. Why is ATP called the energy currency of the cell? ATP is the energy currency of the cell because it contains high energy bonds - energy is released when these bonds are broken. 58. What are 3 differences between DNA and RNA? DNA RNA Sugar deoxyribose ribose Nitrogenous bases A,T,C,G A,U,C,G Shape double helix single helix Polymers, dehydration synthesis and hydrolysis: 59. Hydrolysis involves the a. splitting of water b. splitting by water removal c. joining by adding water d. splitting by adding water 60. Glucose to starch involves a. hydrolysis b. dehydration synthesis c. oxidation d. reduction 61. Starch to glucose involves a. hydrolysis b. dehydration synthesis c. oxidation d. reduction 62. Polymers are broken down by a. dehydration synthesis b. polymerization c. hydrolysis d. autolysis 63. Which of the following can be formed by hydrolysis? a. neutral fat b. glycogen c. cellulose d. glucose 64. Which of the following best relates to dehydration synthesis? a. cellulose to starch b. glucose to glycogen c. starch to glucose d. glycogen to glucose 65. Which of the following best relates to hydrolysis? a. cellulose to starch b. glucose to glycogen c. starch to glucose d. glycogen to amino acids 66. Which of the following is a polymer? a. fructose b. glucose c. amino acid d. starch 67. Which of the following is not a polymer? a. neutral fat b. cellulose c. amino acid d. starch
68. What are the 4 classes of organic polymers? Carbohydrates, proteins, lipids, nucleic acids 69. Which polymers are most concerned with energy? Carbohydrates 70. Which polymers form enzymes? Proteins 71. Which polymers make up chromosomes and genes? Nucleic acids 72. Which 2 polymers may form hormones? Proteins and lipids (steroids)