front 1 Humans and mice differ because: A) their cells make different types of lipids. B) their cells have some differences in the sequence of nucleotides in their nucleic acids. C) their cells make different types of large biological molecules. D) their cells make different types of proteins. E) their cells have different small organic molecules | back 1 their cells have some differences in the sequence of nucleotides in their nucleic acids. |
front 2 Molecules with which functional groups may form polymers via dehydration reactions? A) hydroxyl groups B) either hydroxyl or carboxyl groups C) carbonyl groups D) either carbonyl or carboxyl groups E) carboxyl groups | back 2 either hydroxyl or carboxyl groups |
front 3 Which of these molecules is not formed by dehydration reactions? A) DNA B) protein C) amylase D) disaccharides E) fatty acids | back 3 fatty acids |
front 4 Which of these classes of biological molecules consist of both small molecules and macromolecular polymers? A) carbohydrates B) lipids, carbohydrates, proteins, and nucleic acids all consist of only macromolecular polymers C) nucleic acids D) lipids E) proteins | back 4 carbohydrates |
front 5 Which of the following is not a polymer? A) chitin B) cellulose C) starch D) glucose E) DNA | back 5 glucose |
front 6 What is the chemical reaction mechanism by which cells make polymers from monomers? A) ionic bonding of monomers B) phosphodiester linkages C) hydrolysis D) dehydration reactions E) the formation of disulfide bridges between monomers | back 6 dehydration reactions |
front 7 Which of the following best summarizes the relationship between dehydration reactions and hydrolysis? A) Dehydration reactions can occur only after hydrolysis. B) Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers. C) Dehydration reactions eliminate water from lipid membranes, and hydrolysis makes lipid membranes water permeable. D) Dehydration reactions ionize water molecules and add hydroxyl groups to polymers; hydrolysis reactions release hydroxyl groups from polymers. E) Hydrolysis creates monomers, and dehydration reactions break down polymers. | back 7 Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers. |
front 8 Which of the following polymers contain nitrogen? A) glycogen B) starch C) chitin D) cellulose E) amylopectin | back 8 Chitin |
front 9 The molecular formula for glucose is C6H1206. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions? A) C18 H32 016 B) C18 H10 O15 C) C18 H36 018 D)C3 H6 O3 E) C6 H10 O5 | back 9 C18 H32 016 |
front 10 The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are the "a" form. Which of the following could amylase break down? A) chitin B) glycogen and chitin only C) cellulose D) glycogen E) glycogen, cellulose, and chitin | back 10 Glycogen |
front 11 On food packages, to what does the term insoluble fiber refer? A) amylopectin B) cellulose C) chitin D) polypeptides E) starch | back 11 cellulose |
front 12 molecule with the chemical formula C6 H12 O6 is probably a A) lipid. B) carbohydrate and monosaccharide only. C) carbohydrate and lipid only. D) monosaccharide E) carbohydrate. | back 12 carbohydrate and monosaccharide only |
front 13 Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one, galactose molecule. How is lactose classified? A) as a hexose B) as a monosaccharide C) as a pentose D) as a disaccharide E) as a polysaccharide | back 13 as a disaccharide |
front 14 All of the following are polysaccharides except A) cellulose. B) lactose. C) glycogen. D) chitin. E) amylopectin. | back 14 lactose |
front 15 Which of the following is true of both starch and cellulose? A) They are both structural components of the plant cell wall. B) They are cis-trans isomers of each other. C) They can both be digested by humans. D) They are both used for energy storage in plants. E) They are both polymers of glucose | back 15 They are both polymers of glucose |
front 16 Which of the following is true of cellulose? A) It is a polymer composed of enantiomers of glucose, it is a storage polysaccharide for energy in plant cells, it is digestible by bacteria in the human gut, and it is a major component of plant cell walls. B) It is digestible by bacteria in the human gut. C) It is a major structural component of plant cell walls. D) It is a storage polysaccharide for energy in plant cells. E) It is a polymer composed of enantiomers of glucose. | back 16 It is a major structural component of plant cell walls |
front 17 Humans can digest starch but not cellulose because A) humans have enzymes that can hydrolyze the a glycosidic linkages of starch but not the glycosidic linkages of cellulose. B) the monomer of starch is glucose, while the monomer of cellulose is glucose with a nitrogen-containing group. C) humans have enzymes that can hydrolyze theglycosidic linkages of starch but not the a glycosidic linkages of cellulose. D) the monomer of starch is glucose, while the monomer of cellulose is galactose. E) humans harbor starch-digesting bacteria in the digestive tract. | back 17 Humans have enzymes that can hydrolyze the "a" glycosidic linkages of starch but not the "B" glycosidic linkages of cellulose |
front 18 Which of the following statements conceming saturated fats is not true? A) They contain more hydrogen than unsaturated fats having the same number of carbon atoms. B) They are one of several factors that contribute to atherosclerosis. C) They are more common in animals than in plants. D) They have multiple double bonds in the carbon chains of their fatty acids. E) They generally solidify at room temperature. | back 18 They have multiple double bonds in the carbon chains of their fatty acids |
front 19 A molecule with the formula C18 H36 O2 is probably a A) carbohydrate. B) nucleic acid. C) protein. D) hydrocarbon. E) fatty acid. | back 19 Fatty Acid |
front 20 Which of the following statements is true for the class of biological molecules known as lipids? A) They are made from glycerol, fatty acids, and phosphate. B) They contain less energy than proteins and carbohydrates. C) They contain nitrogen. D) They are made by dehydration reactions. E) They are insoluble in water. | back 20 They are insoluable in water |
front 21 The label on a container of margarine lists "hydrogenated vegetable oil" as the major ingredient. What is the result of adding hydrogens to vegetable oil? A) The hydrogenated vegetable oil has more "kinks" in the fatty acid chains. B) The hydrogenated vegetable oil has fewer trans fatty acids. C) The hydrogenated vegetable oil stays solid at room temperature. D) The hydrogenated vegetable oil has a lower melting point. E) The hydrogenated vegetable oil is less likely to clog arteries | back 21 They hydrogenated vegetable oil stays solid at room temperature |
front 22 Which of the following is true regarding saturated fatty acids? A) They have double bonds between carbon atoms of the fatty acids. B) They are usually produced by plants. C) They are the predominant fatty acid in com oil. D) They are the principal molecules in lard and butter. E) They are usually liquid at room temperature. | back 22 They are the principal molecules in lard and butter |
front 23 Large organic molecules are usually assembled by polymerization of a few kinds of simple subunits. Which of the following is an exception to this statement? A) cellulose B) DNA C) a contractile protein D) an enzyme E) a steroid | back 23 A steroid |
front 24 Which modifications of fatty acids will best keep triglycerides solid at warmer temperatures? A) creating cis double bonds to the fatty acids B) adding hydrogens and trans double bonds to the fatty acids C) creating trans double bonds to the fatty acids D) adding hydrogens to the fatty acids E) adding cis double bonds and trans double bonds to the fatty acids | back 24 adding hydrogens and trans double bonds to the fatty acids |
front 25 Why are human sex hormones considered to be lipids? A) They are not soluble in water. B) They contribute to atherosclerosis. C) They are hydrophilic compounds. D) They are made of fatty acids. E) They are essential components of cell membranes. | back 25 They are not soluable in water |
front 26 All of the following contain amino acids except A) hemoglobin. B) antibodies. C) insulin. D) cholesterol. E) enzymes. | back 26 cholesterol |
front 27 The bonding of two amino acid molecules to form a larger molecule requires A) the addition of a water molecule. B) the release of a water molecule. C) the release of a nitrous oxide molecule. D) the release of a carbon dioxide molecule. E) the addition of a nitrogen atom | back 27 The release of a water molecule |
front 28 There are 20 different amino acids. What makes one amino acid different from another? A) different structural and optical isomers B) different asymmetric carbons C) different side chains (R groups) attached to the amino groups D) different side chains (R groups) attached to a carboxyl carbon E) different side chains (R groups) attached to an a carbon | back 28 different side chains (R groups) attached to an "a" carbon |
front 29 The bonding of two amino acid molecules to form a larger molecule requires which of the following? A) removal of a water molecule B) both removal of a water molecule and formation of a hydrogen bond C) formation of a hydrogen bond D) addition of a water molecule E) formation of a glycosidic bond | back 29 removal of a water molecule |
front 30 Polysaccharides, triacylglycerides, and proteins are similar in that they A) are synthesized from subunits by dehydration reactions. B) all contain nitrogen in their monomer building blocks. C) are decomposed into their subunits by dehydration reactions. D) are synthesized as a result of peptide bond formation between monomers. E) are synthesized from monomers by the process of hydrolysis. | back 30 are synthesized from subunits by dehydration reactions |
front 31 Dehydration reactions are used in forming which of the following compounds? A) triacylglycerides and proteins only B) triacylglycerides C) triacylglycerides, polysaccharides, and proteins D) polysaccharides E) proteins | back 31 triacylglycerides, polysaccharides, and proteins |
front 32 What aspects of protein structure are stabilized or assisted by hydrogen bonds? A) secondary structure B) quaternary structure C) primary structure D) secondary, tertiary, and quaternary structures, but not primary structure E) tertiary structure | back 32 secondary, tertiary, and quaternary structures, but not primary structure |
front 33 Which bonds are created during the formation of the primary structure of a protein? A) peptide bonds B) peptide bonds, hydrogen bonds, and disulfide bonds C) disulfide bonds D) phosphodiester bonds E) hydrogen bonds | back 33 peptide bonds |
front 34 What maintains the secondary structure of a protein? A) hydrogen bonds between the amino group of one peptide bond and the carboxyl group of another peptide bond B) disulfide bonds C) hydrophobic interactions D) peptide bonds E) hydrogen bonds between the R groups | back 34 hydrogen bonds between the amino group of one peptide bond and the carboxyl group of another peptide bond |
front 35 Which type of interaction stabilizes the a helix and the "B" pleated sheet structures of proteins? A) peptide bonds B) ionic bonds C) disulfide bonds D) hydrogen bonds E) hydrophobic interactions | back 35 hydrogen bonds |
front 36 Which level of protein structure do the "a" helix and the "B" pleated sheet represent? A) secondary B) primary C) tertiary D) primary, secondary, tertiary, and quaternary E) quaternary | back 36 secondary |
front 37 The amino acids of the protein keratin are arranged predominantly in an "a" helix. This secondary structure is stabilized by: A) ionic bonds. B) hydrogen bonds. C) peptide bonds. D) covalent bonds. E) polar bonds. | back 37 hydrogen bonds |
front 38 The tertiary structure of a protein is the: A) Organization of a polypeptide chain into a "A" helix or "B" pleated sheet B) Overall protein structure resulting from the aggregation of two or more polypeptide subunits C) Bonding together of several polypeptide chains by weak bonds D) unique three-dimensional shape of the fully folded polypeptide E) Order in which amino acids are joined in polypeptic chain | back 38 unique three-dimensional shape of fully folded polypeptide |
front 39 Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded polypeptides? A) diabetes mellitus only B) Alzheimer's and Parkinson's only C) Alzheimer's, Parkinson's, and diabetes mellitus D) Parkinson's only E) Alzheimer's only | back 39 Alzheimer's and Parkinson's only |
front 40 What methods may be used to elucidate the structures of purified proteins? A) X-ray crystallography B) both X-ray crystallography and NMR spectroscopy C) NMR spectroscopy D) bioinformatics E) analysis of amino acid sequence of small fragments | back 40 analysis of amino acid sequence of small fragments |
front 41 In a normal cellular protein, where would you expect to find a hydrophobic amino acid like valine? A) in the interior of the folded protein, away from water B) on the exterior surface of the protein, interacting with water C) in the interior of the folded protein, away from water, or in a transmembrane portion interacting with lipid fatty acid chains D) anywhere in the protein, with equal probability E) in the transmembrane portion interacting with lipid fatty acid chains | back 41 in the interior of the folded protein, away from water, or in a transmembrane portion interacting with lipid fatty acid chains |
front 42 Which of the following techniques uses the amino acid sequences of polypeptides to predict a protein's threedimensional structure? A) bioinformatics B) analysis of amino acid sequence of small fragments C) NMR spectroscopy D) high-speed centrifugation E) X-ray crystallography | back 42 bioinformatics |
front 43 One of the primary functions of RNA molecules is to: A) transmit genetic information to offspring B) Form the genes of higher organisms C) Act as a pattern or blueprint to form DNA D) Function in the synthesis of protiens E) make a copy of itself, thus ensureing genetic continuity | back 43 function in the synthesis of proteins |
front 44 Which of the following descriptions best fits the class of molecules known as nucleotides? A) a pentose sugar and a purine or pyrimidine B) a nitrogenous base and a pentose sugar C) a phosphate group and an adenine or uracil D) a nitrogenous base and a phosphate group E) a nitrogenous base, a phosphate group, and a pentose sugar | back 44 a nitrogenous base, a phosphate group and a pentose sugar |
front 45 Which of the following are nitrogenous bases of the pyrimidine type? A) ribose and deoxyribose B) guanine and adenine C) adenine and thymine D) cytosine and uracil E) thymine and guanine | back 45 cytosine and uracil |
front 46 Which of the following are nitrogenous bases of the purine type? A) adenine and thymine B) cytosine and guanine C) uracil and cytosine D) guanine and adenine E) thymine and uracil | back 46 guanine and adenine |
front 47 Which of the following is an example of hydrolysis? A) the reaction of a fat, forming glycerol and fatty acids with the consumption of water B) the reaction of two monosaccharides, forming a disaccharide with the release of water C) the synthesis of a nucleotide from a phosphate, a pentose sugar, and a nitrogenous base with the production of a molecule of water D) the synthesis of two amino acids, forming a peptide with the release of water E) the reaction of a fat, forming glycerol and fatty acids with the release of water | back 47 the reaction of a fat, forming glycerol and fatty acids with the consumption of water |
front 48 Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA? A) 5'-ATGC-3' with 5'-GCAT-3' B) 5'-AGCT-3' with 5'-TCGA-3' C) 5'-purine-pyrimidine-purine-pyrimidine-3' with 3'-purine-pyrimidine-purine-pyrimidine-5' D) 5'-GCGC-3' with 5'-TATA-3' E) All of these pairs are correct. | back 48 5'-ATGC-3' with 5'-GCAT-3' |