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Problem 7c
Draw the structure for the amino acid represented by each of the following abbreviations:
c. Q
Problem 7d
Draw the structure for the amino acid represented by each of the following abbreviations:
d. Ile
Problem 8d
Draw the structure for the amino acid represented by each of the following abbreviations:
d. Y
Problem 10.1b
Draw the structure for each of the following amino acids and put an asterisk (*) next to any chiral carbon centers in your structure:
b. lysine
Problem 10.104
Meats spoil due to the action of enzymes that degrade the proteins. Fresh meats can be preserved for long periods of time by freezing them. Explain how freezing meats works to prevent spoilage.
Problem 10.11b
Isoleucine has the zwitterion structure shown. Draw the structure and give the net charge of isoleucine that will predominate at the indicated pH values (pI = 6.0).
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b. pH 6.0
Problem 10.13a
Write the products for the following condensation or hydrolysis reactions:
a. <IMAGE>
Problem 10.15
Consider the following tripeptide:
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a. Circle the N-terminal amino acid, and give its name. Draw a square around the C-terminal amino acid, and give its name.
Problem 10.16b
Consider the following tripeptide:
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b. Give the one-letter and three-letter abbreviations of this tripeptide.
Problem 10.17b
Draw the structural formula for each of the following peptides:
b. KCG
Problem 10.17c
Draw the structural formula for each of the following peptides:
c. His—Met—Gln
Problem 10.18c
Draw the structural formula for each of the following peptides:
c. Val—Arg
Problem 10.18d
Draw the structural formula for each of the following peptides:
d. IYP
Problem 10.2
Classify each of the amino acids in Problem 10.1 as polar (neutral, acidic, or basic) or nonpolar and as hydrophobic or hydrophilic.
Problem 10.28b
Determine whether each of the following statements describes the primary, secondary, tertiary, or quaternary structure of a protein.
b. Peptide bonds join amino acids in a polypeptide chain.
Problem 10.28d
Determine whether each of the following statements describes the primary, secondary, tertiary, or quaternary structure of a protein.
d. Hydrogen bonding between amino acids in the same polypeptide gives a coiled shape to the protein.
Problem 10.29b
Determine whether each of the following statements describes the primary, secondary, tertiary, or quaternary structure of a protein.
b. Hydrogen bonds form between adjacent segments of the backbone of the same protein to form a “folded-fan” structure.
Problem 10.29d
Determine whether each of the following statements describes the primary, secondary, tertiary, or quaternary structure of a protein.
d. Amino acids react in a condensation reaction to form a peptide bond.
Problem 10.3
Give the three-letter and one-letter abbreviations and identify the functional group in the side chain for each amino acid in Problem 10.1.
Problem 10.33a
List the type of attractive force disrupted and the level of protein structure changed by the following denaturing treatments:
a. adding salt to soy milk to make tofu
Problem 10.35a
Identify each of the following statements as characteristic of protein denaturation or protein hydrolysis.
a. Milk curdles when lemon juice is added to it.
Problem 10.35b
Identify each of the following statements as characteristic of protein denaturation or protein hydrolysis.
b. A protein breaks up into amino acid fragments.
Problem 10.37b
Match each protein in column A with its function in column B:
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Problem 10.4c
Draw the structure for each of the following amino acids and put an asterisk (*) next to any chiral carbon centers in your structure:
c. methionine
Problem 10.42
What is the name given to the reactant of an enzyme-catalyzed reaction?
Problem 10.44
What is the name given to a small, organic nonprotein part of an enzyme that is involved in catalysis?
Problem 10.49
What level of protein structure is involved in the formation of an enzyme’s active site?
Problem 10.5
Classify each amino acid in Problem 10.4 as polar (neutral, acidic, or basic) or nonpolar and as hydrophobic or hydrophilic.
Problem 10.50
What kind of interaction attracts the cofactor Mg²⁺ and ATP to each other? (Hint: Look at the structure of the phosphate group.)
Problem 10.51a
How would the following changes affect enzyme activity for an enzyme whose optimal conditions are normal body temperature and physiological pH?
a. raising the temperature from 37 °C to 60 °C
