Exam 3: Proteins, Carbohydrates, and Lipids

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Phospholipid bilayer...

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A) are polymers.
B) are simple sugars.
C) are found in biological membranes.
D) have the general structure (C₁H₂O₁) _n or C_nH_2nO_n.
E) are more soluble in nonpolar solvents than in water.

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Both structures contain a glycerol backb...

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A) structural isomers.
B) optical isomers.
C) hydrophobic.
D) monosaccharides.
E) fatty acids.

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A) double bonds
B) glycosidic linkages
C) peptide bonds
D) disulfide bridges
E) van der Waals forces

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A) Humans and chimpanzees are so closely related that all of their protein sequences are identical.
B) The two proteins serve the same function in both humans and chimpanzees because their structures are the same.
C) The folding is likely to differ in the polypeptide chains in the two cases because they exist in cells of different organisms.
D) The two proteins will have the same properties, since they have the same primary structure, but different functions, since they come from different species.
E) The biological properties of the two proteins must differ, since they were isolated from two different species.

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A) has a higher number of carbon-carbon double bonds.
B) has a lower number of carbon-carbon double bonds.
C) is a saturated fat, and sample B is an unsaturated fat.
D) is an unsaturated fat, and sample B is a saturated fat.
E) is a triglyceride, and sample B is a simple lipid.

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A) wax.
B) phospholipid.
C) fat-soluble vitamin.
D) steroid.
E) carotenoid.

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A) 10⁵⁰
B) 20⁵⁰
C) 20 × 50
D) 50²⁰
E) 50 × 50

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A) Two proteins isolated from modern terrestrial animals such as fruit flies and lizards should be closely related, which implies that the two molecules will function in the same way.
B) Two proteins with the same distribution of amino acids have the same size, which allows the two molecules to function in the same way.
C) Two proteins made up of the same number and types of amino acids have the same composition, which allows the two molecules to function in the same way.
D) Two proteins with the same amino acid composition have the same mass, which allows the two molecules to function in the same way.
E) Two proteins with the same amino acid sequence have the same structure, which allows the two molecules to function in the same way.

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A) Large changes in sizes of amino acid side chains disrupt the tertiary structure in this region of the protein.
B) The tertiary structure of this section of the protein is stabilized by salt bridges between amino acid residues.
C) Disruption of hydrophobic interactions in this section of the protein leads to decreased stability of its tertiary structure.
D) Protein stability does not change no matter what amino acid is inserted at certain positions in the polypeptide chain.
E) Protein stability always decreases whenever any amino acid change is made at certain positions in the polypeptide chain.

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A) Energy storage
B) Energy source
C) Energy transport
D) Carbon skeleton source
E) Structural support

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A) nucleotides.
B) trisaccharides.
C) monosaccharides.
D) nucleosides.
E) fatty acids.

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A) Add a phosphate group onto one of the carbons of the glycerol backbone.
B) Add a phosphate group onto the end of one of the hydrocarbon tails.
C) Add a phosphate group onto the carbonyl carbon connecting one of the fatty acids to the glycerol backbone.
D) Replace one of the fatty acids bonded to the glycerol backbone with a phosphate group.
E) Replace one of the glycerol backbone carbons with a phosphate group.

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A) be a signal from one part of the body to the other.
B) color the leaves of a tree.
C) prevent feathers from getting wet.
D) store energy.
E) dissolve polar substances.

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A) The claim is correct because all triglycerides have the same pattern of ester linkages between fatty acids and glycerol.
B) The claim is correct because all fatty acid tails consist of long hydrocarbon tails that contribute to the nonpolar nature of triglycerides as a class.
C) The claim is incorrect because triglycerides can assume different shapes due to random motion of their hydrocarbon chains.
D) The claim is incorrect because the hydrocarbon chains of triglycerides vary in length and number of double bonds.
E) The claim is incorrect because triglycerides are found in many different types of organisms.

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Complex carbohydrates are easily broken ...

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