Multiple Choice Questions - CHOOSE THE BEST ANSWER

Multiple Choice Questions - CHOOSE THE BEST ANSWER 1. Which of the following statements does not describe a property or characteristic of glucose. a) Glucose is an aldoheptose. b) Glucose has two enantiomers, D-Glucose and L-Glucose. c) Glucose is the most common naturally occurring monosaccharide in nature. d) Glucose is stored in the body as glycogen.

2. Aldoses are sugars: a) having an aldehyde functional group. b) having only six carbon atoms per molecule. c) which always give a positive Benedict's test as well as a positive Tollen's test. d) which form the polysaccharide glycogen.

3. Fructose is: a) an aldopentose sugar. b) a non reducing sugar. c) a monosaccharide of lactose. d) also known as levulose.

4. The condensation of galactose and glucose produces the disaccharide: a) sucrose b) dextrose c) lactose d) maltose

5. Which of the following statements is not true, in general, about carbohydrates? a) They are made up of only carbon, hydrogen and oxygen atoms. b) Their oxygen to hydrogen ratio of about 2:2. c) Their solubility in water is a result of the many hydroxyl groups dispersed through out the molecule. d) They can be classified either according to their length or functional group.

6. Which of the following characteristics of chirality is not true? a) The carbon atom is single bonded to four different atoms or groups of atoms. b) The chiral carbon atom is said to be unsaturated. c) Chiral molecules have optically active isomers. d) Chiral molecules have two enantiomers.

7. A compound whose molecular structure rotates polarized light counterclockwise: a) is designated as being dextrorotatory. b) always has two chiral carbon centers. c) is designated as being levoratatory. d) belongs to the most abundant or naturally occurring group of carbohydrate enantiomers.

8. Cooked foods are easier to digest because: a) carbohydrates are soluble in water. b) indigestible polysaccharides, such as starch and cellulose have been completely or partial hydrolyzed to maltose. c) heating destroys the carbonyl bond within these compounds. d) the glycosidic linkages have condensed producing a mixture of dextrin, maltose and glucose.

9. The smallest unit any carbohydrate can be hydrolyzed to is a: a) monosaccharide b) disaccharide c) glucose d) hemiacetal

10. The actual ring structure of a carbohydrate is not a true ring shape as is drawn when using the formulas, but really should be drawn in a form. a) Fischer projection, oval ring b) molecular, straight-chain c) Haworth, puckered ring d) chemical, cyclic

11. Which of the following statements does not accurately characterize or describe enantiomers: a) When enantiomers are equally mixed together they become optically active. b) Enantiomers are compounds who have a mirror image or twin-like molecular structures. c) In nature, enantiomers tend to illicit very different responses in organisms. d) Enantiomers have identical chemical and physical properties. 12. Glucose is stored in the body as: a) sucrose b) lactose c) starch d) glycogen 13. The designations alpha and beta indicates whether the on the carbon numbered as #1 in a monosaccharide is or the plane of the molecule. a) carbonyl group, within, outside b) chiral group, above, within c) hydroxyl group, below, above d) oxygen atom, below, outside 14. The designations alpha and beta indicates the position of the between two monosaccharides in a . a) hydroxyl group, covalent bond b) oxygen atom, glycosidic linkage c) carbonyl group, polar covalent bond d) carbon atom, branched linkage 15. To make some starches more soluble, phosphate ester groups are inserted into these straight-chain molecules. Inserting phosphate ester groups . a) disrupts the molecule's intermolecular forces thereby permitting water to disperse within the chain more effectively. b) changes the chemical composition of the starches, thereby decreasing their polarity. c) alters their optical reactivity and thus causes their solubility to increase. d) all of the above are true. 16. The Benedict's test is used to determine whether or not a mono or disaccharide is a: a) simple sugar b) reducing sugar c) pentose sugar d) polyhydroxyl sugar 17. The final product produced when starch is completely hydrolyzed is: a) dextrin b) sucrose c) glucose d) carbon dioxide 18. A glycosidic linkage is between two monosaccharides. a) a polar covalent bond b) is a true covalent bond c) a ionic bond d) is a hydrogen bond 19. Fructose is also known as levulose. This name suggest that fructose most abundant enantiomer: a) rotates polarize light clockwise. b) rotates polarized light counterclockwise. c) is an aldopentose sugar. d) is a ketoheptose sugar. 20. The reactions of photosynthesis: a) produce carbon dioxide and glucose. b) can be classified into two categories - light and dark. c) all require radiant energy to proceed. d) all take place in the plant's mitochondria. 21. There is a(n) relationship between the number of unsaturated bonds in a fatty acid and their melting point. As the degree of unsaturation in the fatty acid's carbon chain, its melting point will . a) direct, decreases, also decrease b) direct, increases, also increase c) inverse, decreases, increase d) inverse, increases, decrease 22. Soap improves the cleansing power of water, because soap molecules have two portions: a) a hydrophobic tail and a hydrophilic head b) a hydrophilic tail and a hydrophobic head c) a sodium salt tail and a hypotonic head d) a potassium salt tail and a hypertonic head

23. Which of the following statements is not true about a fat or oil's iodine number test: a) It is a measure of the degree of unsaturation in a fat or oil. b) It is the amount of iodine in grams that will react with 100 grams of saponifiable lipid. c) It is an iodination/addition chemical reaction. d) The larger the value of the iodine number the fewer the number of double bonds present in the fat or oil.

24. Oils can be converted to solid fats by: a) halogenation b) hydrogenation c) hydration d) hydrolysis

25. A qualitative test for a fat or oil is the a) tollen's test. b) iodine/starch test. c) benedict's test. d) iodine number test. 26. Fat metabolism diseases, such as the Tay-Sachs disease, are most often associated with having a deficiency in specific enzymes which hydrolyze . In Tay-Sachs, the enzyme -galactosidase, is missing or is present in extreme low quantities. a) phospholipids b) cholesterol c) glycolipids d) triglycerides

27. Glycerol is an alcohol which can be classified as triol. Triols are alcohols which have: a) triple bonds within the molecule. b) three carbon atoms in the molecule. c) three hydroxyl groups dispersed throughout the molecule. d) three carbonyl groups group within the molecule's carbon chain.

28. A fatty acid that contains a mixture of single and double bonds is said to be: a) unsaturated. b) saturated. c) nonsaponifiable. d) saponifiable.

29. Triglycerides are glycerols which have had of their hydroxyl groups esterified with fatty acids. a) none b) one c) two d) all

30. Fatty acids are long chained: a) mineral acids. b) carboxylic acids. c) phosphoric acids. d) weak acids.

31. The bond between a glycerol molecule and a fatty acid in a lipid is called a: a) glyceride bond b) hydrogen bond c) ester bond d) glycosidic bond

32. Cholesterol is synthesized from the compound . a) acetyl coenzyme A (acetyl-CoA) b) cholesterolase c) terpene d) sterol

33. A lipid is a fat or oil which can undergo hydrolysis in alkaline solutions. When triglycerides undergo hydrolysis in an alkaline solution and the salts of the are produced. a) nonsaponifiable, glyceride, fatty acids b) nonsaponifiable, glycerol, acyl fatty acids c) saponifiable, glycerol, fatty acids d) saponifiable, glyceride, acyl fatty acids

34. The rancidity of fats and oils is caused either by the or the of the lipid's fatty acids molecules. a) hydration, reduction b) hybridization, reflexation c) hydrogenation, oxidation d) hydrolysis, oxidation

35. The hydrogenation of a(n) fatty acid converts all the bonds to , bonds. a) saturated, double, saturated, single b) saturated, single, unsaturated double c) unsaturated, double, saturated, single d) unsaturated, single, unsaturated, double

36. Which is not a characteristic of a lipid? a) Lipids are soluble only in non polar solvents such as benzene b) Lipids are a diversified group of compounds, whose common characteristic is that they are insoluble in water. c) Lipids are high sources of energy for the cell. d) Lipids can be classified as either being nonsaponifiable or saponifiable.

37. Unsaturated fatty acids are often grouped by the and of bonds within the molecule's carbon chain. a) number, type, single b) number, placement, double c) number, placement, single d) number, type, double

38. An unsaturated fatty acid given the shorthand code of (14:4n-2) means this particular fatty acid has carbon atoms, bonds, with the first double bond beginning at the carbon from the molecule's methyl end. a) 14, 2 single, second b) 14, 2 double, fourth c) 14, 4 double, second d) 14, 4 single, fourth

39. A simple saponifiable lipid differs from a compound saponifiable lipid by the products it yields when it undergoes: a) saponification b) hydrolysis c) hydrogenation d) hydration

40. Which of the following chemical substances can not be classified as a lipid? a) beef tallow b) linseed oil c) lanolin d) amylose

41. When determining the iodine number for an unsaturated fatty acid, it is the of the molecule that reacts with the iodine. a) carboxylic acid b) hydroxyl group c) alkene bonds d) alkane bonds

Questions #42 through 43 Given the following fatty acid: CH3CH2CH=CHCH2CH=CHCH2CH=CH(CH2)7COOH 42. The shorthand formula code describing this molecule is: a) (12:9n-3) b) (13:3n-3 c) (15:3n-9) d) (18:n-3)

43. An esterification reaction with the two moles of the above fatty acid one mole of glycerol and one mole of galactose would produce a: a) simple lipid b) nonsaponifiable lipid c) glycolipid d) sterol

Questions #44 through #45 Fatty acid labeled #1 has an iodine number of 185, whereas fatty acid labeled #2 has an iodine number of 130. 44. Fatty acid #1: a) has a higher melting point than fatty acid #2 b) has a lower melting point than fatty acid #2 c) has the same melting point as fatty acid #2 d) not enough information given

45. Fatty acid #2: a) has a greater degree of unsaturation than fatty acid #1 b) has a greater degree of saturation than fatty acid #1 c) has the same degree of saturation as fatty acid #1 d) not enough information given

Questions #46 through #50 Given the following amino acid and their alkyl (-R) groups: alanine -CH3 asparagine -CH2 - COOH serine -CH2 - OH lysine -(CH2)4 - NH2 46. The amino acid which would be least soluble in water.

47. The amino acid when undergoing an oxidation reaction would yield a aldehyde group.

48. The amino acid whose chemical and physical properties are most similar to ethanamine:

49. The amino acid whose pI would be the most acidic.

50. The amino acid(s) which when placed in an electric field at a pH of 7 would migrate towards the positive pole.

Questions #51 through #55 Given the following: Phe-Asn-Ala-His 51. The above amino acid sequence in an example of a: a) peptide b) dipeptide c) tripeptide d) oligopeptide

52. If the above molecule were to be placed in an electric field a pH of 7 the molecule would most likely: a) migrate towards the positive pole. b) migrate towards the negative pole. c) not migrate at all. d) not go into solution.

53. The N-terminal end of the above molecule is the amino acid: a) Ala b) Phe c) His d) Asn

54. The above amino acid sequence is an example of a protein's: a) primary structure b) secondary structure c) tertiary structure d) quaternary structure

55. The zwitterion structure of the above molecule is: a) H3N+-Phe-Asn-Ala-His-COOH b) H2N+-Phe-Asn-Ala-His-COO- c) H3N+-Phe-Asn-Ala-His-COO- d) H2N-Phe-Asn-Ala-His-COO-

56. Given the following amino acids and their alkyl (-R) groups glycine (R group is -H) aspartic acid (R group is -CH2COOH) serine (R group is -CH2OH) lysine (R group is -(CH2)4NH2) The amino acid which is optically inactive is: a) glycine b) aspartic acid c) serine d) lysine

57. Which of the following is not a characteristic of a globular protein. a) They are soluble in water. b) Their function is primarily one of protection and structure. c) Myoglobin is an example of a globular protein. d) Its quaternary and tertiary structure play an important role in its functionality.

58. Which of the following is not an interaction or linkage observed in maintaining a protein's tertiary structure: a) disulfide bridges b) hydrophobic interactions c) hydrogen bonding d) ionic bonding

59. The ionic interactions between lysine's amino group and aspartic acid's carbonyl group result in the formations of in a protein's tertiary structure. a) hydrophilic bridges b) amide linkages c) salt bridges d) peptide linkages

60. The interaction or bonding most prevalent in a protein's secondary structure is: a) amide linkage b) disulfide bridges c) salt bridges d) hydrogen bonding

61. Organic reagents, such as ethanol, have the greatest disruptive effect on a protein's native configuration because: a) they disrupt the disulfide bridges between cysteine molecules. b) they interfere with the hydrophobic interactions between the non polar amino acid side chains. c) they disrupt the hydrogen bonding and salt bridges between the protein's amino acids. d) they disrupt the amide linkages between the individual amino acids.

62. The bond between individual amino acid molecules is called a peptide bond. A peptide bond is a(n) a) ester bond b) amide bond c) ionic bond d) amine bond

63. A protein's tertiary structure can be described as: a) its amino acid sequence b) the spatial arrangement of its subunits c) its folding pattern d) its helical structure

64. Denaturation is the disruption of a protein's tertiary structure. Which of the following solvents would not have denature a protein. a) ethanol b) acetone c) acetic acid d) water

65. A protein is soluble at its . a) most, normal pH b) least, normal pH c) least, pI d) most, pI

66. Which of the following is not part of an enzyme molecule. a) coenzyme b) apoenzyme c) proenzyme d) cofactor

67. Which of the following does not describe the active site of an enzyme: a) It is enantiomer specific. b) Only one active site exists per enzyme molecule. c) It is the area where the substrate and enzyme interact. d) Its configuration or shape is determined by the protein's primary structure.

68. Which of the following statements is true. a) All enzymatic activity requires the use of cofactors. b) The apoenzyme is a part of all enzymes. c) Proenzymes are active enzymes. d) Holoenzymes are inactive enzymes.

Questions #69 through #73 Given the following general classification of enzymes: oxidases isomerases peptidases hydrolases dehydrogenases esterases 69. Ribonuclease hydrolyzes ribonucleic acids. Its enzymes is part of a class of enzymes known as the ______70. Enzymes which catalyze the removal of hydrogen atoms from a substrate belong to the _________group of enzymes. 71. The amide linkages between amino acid groups in a protein are very stable and inert from changes in pH, solvents and salt concentrations. These bonds can be broken by the _________. 72. In order for oxygen to combine with a substrate it must be activated by this class of enzymes, the _________ 73. For L-fructose to be used as a source of energy, it is sometimes converted to D-glucose. The class of enzymes responsible for the conversion of L-fructose to D-glucose would be the ________ 74. When an amino acid's functional group at the enzyme's active site or a cofactor, such as iron, are destroyed or permanently altered, the enzyme's functionality decease. This type of enzyme inhibition is referred to as . a) denaturation inhibition b) irreversible inhibition c) reversible inhibition d) active site inhibition

75. inhibition of a enzyme's activity can result from either inhibition, where an inhibitor alters the tertiary shape of the enzyme or inhibition, where an inhibitor vies with the substrate for the enzyme's active site. a) Irreversible, competitive, noncompetitive b) Irreversible, noncompetitive, competitive c) Reversible, competitive, noncompetitive d) Reversible, noncompetitive, competitive

76. The use of antibiotics to fight bacteria infections and 5-flurouracil, an antimetabolite used to destroy cancer cells, both work by an enzyme's activity. a) irreversibly inhibiting b) destroying c) reversibly inhibiting d) denaturalizing

77. The or enzyme is inhibited by the final or end product of a multienzyme step metabolic process. This type of enzyme activity inhibition is referred to as inhibition. a) regulatory, allosteric, feedback b) apoenzyme, regulatory, noncompetitive c) coenzyme, allosteric, competitive d) proenzyme, substrate-bond, irreversible

78. Which of the following statements is not true about allosteric enzymes. a) They can be inhibited by the end product of a metabolic process they initially catalyzed. b) They are usually large, complex, high molecular weight holoenzymes. c) Their flexibility allows them to deactivate an enzyme's active site, thus making the site more or less receptive to the substrate. d) They have only one site of attachment for both the substrate and the regulatory enzyme.

79. Hormones are considered to be messengers, whereas cyclic AMP acts as a messenger. Cyclic Amp is activated only when a hormone . a) proenzyme, intracellular, passes through the cell membrane and attaches itself to a receptor site in the cell's nucleus. b) primary, secondary, attaches at a specific receptor site on the outside of the cellular membrane. c) intercellular, intracellular, attaches itself to the enzyme's active site. d) coenzyme, proenzyme, passes through the cell membrane and attaches itself to the cell's intracellular receptor site.

80. Which of the following statements do not describe a characteristic of a vitamin. a) Vitamins need to be supplemented through diet because either the body can not manufacture the vitamin or it can not synthesize sufficient amounts to promote cellular function, growth, repair and/or reproduction. b) Vitamins can be polar or non polar. c) Vitamins can act as coenzymes in some metabolic reactions. d) Vitamins are small organic or inorganic molecules.

81. The first step in the Lock and Key theory of enzyme specificity can be illustrated by the following symbolic notation: a) S (substrate) P (product) b) E (enzyme) + P (product) EP (enzyme-product complex) c) E (enzyme) + S (substrate) ES (enzyme-substrate complex) d) ES (enzyme-substrate complex) E (enzyme) + P (product)

82. In an enzymatic reaction, the ES or enzyme-substrate complex, actually represents: a) the activated complex in a catalyzed reaction. b) the prereactant in a catalyzed reaction. c) the energy of activation in a catalyzed reaction. d) the allosteric enzyme in a catalyzed reaction.

83. A noncompetitive inhibition reaction can be symbolically illustrated as: a) E (enzyme) + I (inhibitor)IP (inhibitor-product complex) b) EI (enzyme-inhibitor complex) + P (product) EP (enzyme-product complex) + I (inhibitor) c) E (enzyme) + S (substrate) (enzyme-substrate complex) d) ES (enzyme-substrate complex) + (inhibitor) ESI (enzyme-substrate-inhibitor complex)

84. This vitamin is essential for the synthesis of prothrombin, a blood-clotting agent. a) Vitamin B b) Vitamin C c) Vitamin D d) Vitamin K 85. A deficiency of this vitamin can result in defective collagen. a) Vitamin B b) Vitamin C c) Vitamin D d) Vitamin K 86. Which of the following facts is not true about acetyl-CoA. a) It is a two carbon molecule. b) It is a common constituent in the metabolism of carbohydrates, lipids and proteins. c) It is produced from the oxidation of pyruvate to acetic acid and forms an ester linkage with coenzyme A. d) It is the initial step of the citric acid cycle. 87. The hydrolysis of high energy compounds, such as ATP: a) produce twice as much energy compared to other phosphate bonds. b) have a positive H value. c) require aerobic conditions. d) is an endothermic process. 88. The unusually high amount of potential energy stored in a molecule of ATP: a) is due to the instability of the molecule. b) results from the specific spatial arrangement of the atoms in the molecule. c) results from the molecule having three oxygen to phosphorous bonds. d) all of the above. 89. Which is not a characteristic of bile. a) Bile salts are used to emulsify fats in the small intestines. b) Cholesterol is a precursor for bile salts. c) Bile is a mixture of bile salts, bile pigments, phospholipids and cholesterol. d) bile is continuously produced by the liver and stored in the pancreas. 90. The enzyme responsible for the digestion of starch in the mouth is: a) amylase b) glucosase c) peptidase d) carboylase 91. Insulin: a) is produced by the alpha cells of the pancreas. b) aids in the passage of glucose into various organs and tissues c) is activated by the hormone glucagon. d) all of the above.

92. The end products of the anaerobic stage of cellular respiration are: a) carbon dioxide, water and ATP b) acetyl-CoA and ATP c) lactic acid, water and ATP d) carbon dioxide, water and ADP 93. Which of the following statements is not true about glycolysis. a) It is an emergency energy-producing process. b) It is the first stage of cellular respiration. c) It occurs in the cytoplasm of a eukaryotic cell. d) Its end products are pyruvic acid, water and 2 ATP. 94. Which of the following statements does not describe the aerobic stage of cellular respiration. a) The site of aerobic cellular respiration is the cell's mitochondria. b) It occurs in two independent set of metabolic reactions, the citric acid cycle and the electron transport chain. c) A total of 34 ATP molecules are produced in this stage of cellular respiration. d) The end products of the aerobic stage of cellular respiration are water, carbon dioxide and ATP. 95. The electron transport or respiratory chain of the aerobic oxidation of glucose: a) produces the majority of the ATP in the entire cellular respiration process. b) is independent of the citric acid cycle. c) is the final hydrogen donor in the respiratory cycle. d) takes place in the cell's cytoplasm. 96. The lactic acid cycle: a) is another name for glycolysis. b) is an anaerobic process. c) is the final step in glycolysis. d) is an aerobic process. 97. Fermentation is: a) an aerobic process b) is a process which is similar to the citric acid cycle. c) a process whose end products are independent of the organism it is taking place. d) is an anaerobic process. 98. Which of the following characteristics describes lipid metabolism. a) The synthesis of lipids from stored fatty acids in the body's adipose tissue is called lipogenesis. b) A dynamic equilibrium exists between the lipids flowing in the blood stream and the fatty acids stored in the adipose tissue. c) Lipid metabolism produces more energy per mass than cellular respiration. d) All of the above. 99. The complete beta oxidation of a 16-carbon fatty acid would yield ATP molecules. a) 36 b) 72 c) 114 d) 130 100. Ketosis: a) is the metabolic process of ketone bodies being produced from excess acetyl-CoA. b) is where the pH of the blood drops because of the presents of excess ketone bodies. c) describes the normal circulation of ketone bodies in the blood stream d) is the hydrolysis of acetyl-CoA to acetone 101. The main dietary source of nitrogen is: a) the metabolism and absorption of amino acids into the blood stream b) the oxidation of urea and its subsequent absorption by the kidneys c) the catabolism and transamination of niacin d) the oxidative deamination of amino acids and their eventually absorption into the blood stream 102. Urea is: a) the medical name for urine b) is the common name for ammonia c) is the converted non toxic form of ammonia d) is the carbamyl phosphate of ornithine 103. Amino acids are synthesized from other free amino acids and also from -keto acids by . a) oxidative deamination b) transamination c) translation d) ornithination 104. The fatty acid cycle removes units per cycle, until the fatty acid has been completely oxidized. a) one carbon b) one acetyl-CoA c) two carbon d) four acetyl-CoA 105. is the metabolic pathway that prepares amino acids for entrance into the citric acid cycle. a) transamination b) transamidation c) oxidative phosphorylation d) oxidative deamination 106. Which of the following is not a characteristic of both RNA and DNA. a) The backbone for each strand of DNA and RNA is composed of a phosphate group and a pentose sugar unit. b) Each nucleic acid has a similar set of purina base pairs. c) Each nucleic acid does exist as a single strand, however, DNA in its native state is found in a double helix conformation. d) Both nucleic acids are involved directly in the transcription process of protein synthesis.

107. are the nitrogen-containing bases which consist of a double heterocyclic nitrogen ring. a) cytosine b) purines c) uracil d) pyrimidines 108. A polypeptide consists of 48 amino acid residues. The minimum number of base pairs in a DNA strand needed to code for this particular polypeptide would be: a) 48 b) 24 c) 16 d) not enough information given 109. The ordering of nucleotides in nucleic acids is an example of its: a) primary structure b) secondary structure c) tertiary structure d) quaternary structure 110. DNA's double helix conformation is an example of the nucleic acid's: a) primary structure b) secondary structure c) tertiary structure d) quaternary structure 111. The intermolecular force responsible for native DNA's double helical shape is: a) salt bridges b) disulfide linkages c) London forces d) hydrogen bonding 112. The replication process of DNA is controlled to assure exact copies of DNA during mitosis through . a) identical base pairing b) complementary base pairing c) opposite base pairing d) differential base pairing 113. Which of the following nitrogen bases do not participate directly in transcription. a) Adenine b) Cytosine c) thymine d) uracil 114. DNA is found in a cell's: a) cytoplasm b) endoplasmic reticulum c) nucleus d) histones 115. is associated with , whereas is associated with . a) mRNA, translation, tRNA, transcription b) mRNA, transcription, tRNA, translation c) rRNA, translation, tRNA, transcription d) rRNA, transcription, hnRNA, translation 116. Which of the following is not involved at any step during protein synthesis. a) DNA b) mRNA c) rRNA d) hnRNA 117. During translation, attaches itself to the located in the cell's endoplasmic reticulum. a) hnRNA, ribosomes b) tRNA, ribosomes c) rRNA, ribosomes d) mRNA, ribosomes 118. The is the language of hereditary information. a) genome b) generic code c) genetic code d) genes 119. The three nucleotide base sequence of is referred to as the . a) mRNA, anticodon b) tRNA, anticodon c) tRNA, codon d) rRNA, codon 120. Given the following portion of a DNA strand: C T A G G G C A A T T G Its complementary daughter strand would have the following base pair sequence: a) G A T C C C T T A A C b) G U T C C C T T U U C c) G A U C C C U U A A C d) C U U T T G C C T A G

121. Given the following portion of a DNA strand: C T A G G G C A A T T G The mRNA strand would have the following base pair sequence: a) G A T C C C T T A A C b) G U T C C C T T U U C c) G A U C C C U U A A C d) C U U T T G C C T A G

122. Which of the following statements is not true. a) Every amino acid residue has its own tRNA. b) In a codon, the first two base pairs remain constant for a given amino acid residue; it is the third base pair which may differ. c) All codons code for an amino acid. d) Codons are universal, they do not change between species.

123. In Eukaryotic cells, segments within a DNA molecule which do not code for an amino acid are referred to as and the areas within the DNA molecule that do code for amino acids is called . a) introns, exons b) anticodons, introns c) codons, exons d) exons, introns

124. The intermolecular force responsible for codon and anticodon interaction is: a) ribosomal linkages b) hydrogen bonding c) salt bridges d) disulfide linkages

125. A is a small, circular piece of DNA found in the bacterial of E. Coli. a) bacterial DNA b) Recombinant DNA c) clonoid d) plasmid