Download Amino Acids, Peptides and Proteins

Amino Acids, Peptides and Proteins
1. At very low pH most amino acids is have a _____ charge.
2. Disulfide bonds are formed between two ______________________ amino acids.
3. In the condensation of two amino acids one molecule of ___________ is lost.
4. Amino acids linked together in a chain are called a _____________.
5. Protein in the food we eat is digested by enzymes called ______.
6. A deficiency in vitamin C causes defects in collagen, which is classified as a _____ protein.
7. The protein ______ participates in oxygen dispersal in muscle.
8. A polypeptide can fold into an individual unit of structure called a ______________.
9. A protein that contains more than one subunit is called ______.
10. A secondary structure which forms a coiled shape with a specific repeating pattern, stabilized
by hydrogen bonds, is called a(n)________.
11. The sequence of amino acids in a protein, from N to C-terminus, is referred to as the
_______ structure.
12. Related proteins contain large regions of sequence ______.
13. The purity and size of a protein can be determined by ________.
14. The amino acid which gives the taste of unami is _______.
15. Sickle cell anemia is caused by an amino acid ______.
16. The collective group of all the proteins is called the:
a) protosome.
b) proteome.
c) genome.
d) prion.
e) liposome.
17. Amino acids are considered zwitterions because they:
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Chapter 3
a) exist as dipolar ionic species.
b) were discovered by H. Zwitter.
c) are white solids.
d) are soluble in water.
e) conduct an electric current.
18. The pK values for amino groups are typically in the pH range:
a) 0-2
b) 4-6
c) 6-8
d) 8-10
e) 4-8
19. Amino acids contain the following groups linked to a carbon:
a) an amino group and a carboxylate group.
b) an amino group and an R group .
c) a carboxylate group and an R group.
d) an amino group and a carboxylate group and an R group.
e) none of the above
20. The amino acids with charged side chains include:
a) aspartate, glutamate, lysine and arginine.
b) aspartate, glutamate and glycine.
c) aspartate, lysine and arginine.
d) aspartate, glutamate, lysine, glycine and arginine.
e) none of the above
21. The net charge of the peptide Arg-Phe-Gly-Lys-Glu at pH 7 is:
a) +2
b) +3
c) -2
d) +1
e) -3
22. Which of the following is not an amino acid inserted into proteins by a “dedicated” tRNA?
a) selenocysteine
b) proline
c) phosphoserine
d) glycine
e) asparagine
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Chapter 3
23. In order to design a drug that could enter a cell, a scientist might consider how it would
interact with a ____ protein located on the cellular membrane.
a) defense
b) structural
c) catalytic
d) immune
e) transport
24. Which of the following characteristics is consistent with the description of a fibrous protein,
but not a globular protein?
a) water insoluble
b) dissolved in biological fluids
c) high content of polar amino acids
d) low tensile strength
e) often function as transport proteins
25. The heme found in myoglobin is a:
a) domain.
b) prosthetic group.
c) zinc finger.
d) peptide.
e) none of the above
26. Which of the following is not a type of secondary structure found in proteins?
a)  sheet
b)  helix
c) random coil
d) random turn
e) disulfide bond
27. If designing a drug that inhibited a large, multisubunit enzyme, it would be important to
know how the drug interacted with the:
a) primary structure.
b) mRNA structure.
c) secondary structure.
d) tertiary structure.
e) quaternary structure.
28. Proteins with charges can be separated by _______ chromatography.
a) exclusion
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Chapter 3
b) size
c) affinity
d) ion exchange
e) gel
29. Protein sequences can be determined by:
a) amino acid sequencing of the protein.
b) determining the amino acid composition.
c) sequencing the DNA of the protein’s corresponding gene.
d) a and b
e) a and c
30. Protein sequence data cannot be used to:
a) determine mutations.
b) estimate three-dimensional structure.
c) determine the exact DNA sequence.
d) deduce about biological function.
e) obtain evolutionary data.
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