Question 1

What is the structural formula of glutamic acid (pI = 3.2) at pH = 1?

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 2

When two protein chains combine to form an active protein, the structural level is __________.

Accepted Answer

A)  pleated 
B)  primary 
C)  secondary 
D)  tertiary 
E)  quaternary 
A)  pleated 
B)  primary 
C)  secondary 
D)  tertiary 
E)  quaternary

Question 3

The dipeptide abbreviated as Gly-Lys is the same as the dipeptide abbreviated as Lys-Gly.

Accepted Answer

A) True 
 B)False

Question 4

At what pH would you expect valine, an amino acid with a neutral R group, to be in the zwitterionic form?

Accepted Answer

A)  1 
B)  4 
C)  7 
D)  10 
E)  14 
A)  1 
B)  4 
C)  7 
D)  10 
E)  14

Question 5

Sickle-cell anemia is caused by a change in the primary structure of a subunit of the hemoglobin protein.

Accepted Answer

A) True 
 B)False

Question 6

A chain made of more than 50 amino acids is usually referred to as a(n)

Accepted Answer

A)  peptide. 
B)  protein. 
C)  enzyme. 
D)  globulin. 
E)  hormone. 
A)  peptide. 
B)  protein. 
C)  enzyme. 
D)  globulin. 
E)  hormone.

Question 7

Zwitterions have an overall positive charge.

Accepted Answer

A) True 
 B)False

Question 8

Heavy metals denature proteins by

Accepted Answer

A)  releasing amino acids. 
B)  disrupting hydrophobic interactions. 
C)  changing the pH of the protein solution. 
D)  changing the temperature of the protein solution. 
E)  disrupting disulfide bonds. 
A)  releasing amino acids. 
B)  disrupting hydrophobic interactions. 
C)  changing the pH of the protein solution. 
D)  changing the temperature of the protein solution. 
E)  disrupting disulfide bonds.

Question 9

The interactions that are important in the secondary structure of a protein are

Accepted Answer

A)  hydrogen bonds. 
B)  hydrophobic interactions. 
C)  disulfide bonds. 
D)  salt bridges. 
E)  peptide bonds. 
A)  hydrogen bonds. 
B)  hydrophobic interactions. 
C)  disulfide bonds. 
D)  salt bridges. 
E)  peptide bonds.

Question 10

Hemoglobin is an example of a protein with

Accepted Answer

A)  primary structure only. 
B)  two protein chains held together. 
C)  a globular structure. 
D)  primarily a β-pleated sheet structure. 
E)  primarily an α helix structure. 
A)  primary structure only. 
B)  two protein chains held together. 
C)  a globular structure. 
D)  primarily a β-pleated sheet structure. 
E)  primarily an α helix structure.

Question 11

The secondary structure of collagen is distinguished by

Accepted Answer

A)  single α helix strands. 
B)  double α helix strands. 
C)  many α helixes wound into fibrils. 
D)  a braided triple helix. 
E)  many glycoside links. 
A)  single α helix strands. 
B)  double α helix strands. 
C)  many α helixes wound into fibrils. 
D)  a braided triple helix. 
E)  many glycoside links.

Question 12

Disulfide bonds in a protein chain connect

Accepted Answer

A)  an amine and a carboxylic acid group. 
B)  an alcohol and a carboxylic acid group. 
C)  tryptophan and alanine residues. 
D)  two cysteine residues. 
E)  two asparagine residues. 
A)  an amine and a carboxylic acid group. 
B)  an alcohol and a carboxylic acid group. 
C)  tryptophan and alanine residues. 
D)  two cysteine residues. 
E)  two asparagine residues.

Question 13

Which of the following shows all of the tripeptides that can be formed from one molecule each of lysine (Lys), threonine (Thr), and histidine (His)?

Accepted Answer

A)  Lys-Thr-His 
B)  Lys-Thr-His, Lys-His-Thr, His-Thr-Lys, His-Lys-Thr, Thr-Lys-His, Thr-His-Lys 
C)  Lys-Thr-His, Lys-His-Thr, His-Lys-Thr, Thr-His-Lys 
D)  Lys-Thr-His, Lys-His-Thr, His-Lys-Thr 
E)  Lys-Thr-His, Lys-His-Thr 
A)  Lys-Thr-His 
B)  Lys-Thr-His, Lys-His-Thr, His-Thr-Lys, His-Lys-Thr, Thr-Lys-His, Thr-His-Lys 
C)  Lys-Thr-His, Lys-His-Thr, His-Lys-Thr, Thr-His-Lys 
D)  Lys-Thr-His, Lys-His-Thr, His-Lys-Thr 
E)  Lys-Thr-His, Lys-His-Thr

Question 14

Sucrase, the protein that facilitates the hydrolysis of sucrose, would be classified as a __________ protein.

Accepted Answer

A)  transport 
B)  hormonal 
C)  catalytic 
D)  structural 
E)  contractile 
A)  transport 
B)  hormonal 
C)  catalytic 
D)  structural 
E)  contractile

Question 15

Amino acids that are not synthesized in the body but must be ingested with the diet are called __________ amino acids.

Accepted Answer

The answer of Amino acids that are not synthesized in...

Question 16

The following amino acid R group chain is

Accepted Answer

A)  polar. 
B)  hydrophobic. 
C)  hydrophilic. 
D)  acidic. 
E)  basic. 
A)  polar. 
B)  hydrophobic. 
C)  hydrophilic. 
D)  acidic. 
E)  basic.

Question 17

A zwitterion of any amino acid has a net charge of __________.

Accepted Answer

The answer of A zwitterion of any amino acid has...

Question 18

Glycine is the only naturally occurring amino acid that is

Accepted Answer

A)  negatively charged. 
B)  positively charged. 
C)  neutral. 
D)  in the L- form. 
E)  achiral. 
A)  negatively charged. 
B)  positively charged. 
C)  neutral. 
D)  in the L- form. 
E)  achiral.

Question 19

Classify each protein by function.
-

Accepted Answer

A) hydrophobic 
B) both 
C) hydrophilic 
A) hydrophobic 
B) both 
C) hydrophilic

Question 20

In the peptide Ala-Try-Gly-Phe, the N-terminal amino acid is

Accepted Answer

A)  alanine. 
B)  phenylalanine. 
C)  tryptophan. 
D)  aspartic acid. 
E)  glycine. 
A)  alanine. 
B)  phenylalanine. 
C)  tryptophan. 
D)  aspartic acid. 
E)  glycine.

Exam 19: Amino Acids and Proteins

What is the structural formula of glutamic acid (pI = 3.2) at pH = 1?

When two protein chains combine to form an active protein, the structural level is __________.

The dipeptide abbreviated as Gly-Lys is the same as the dipeptide abbreviated as Lys-Gly.

At what pH would you expect valine, an amino acid with a neutral R group, to be in the zwitterionic form?

Sickle-cell anemia is caused by a change in the primary structure of a subunit of the hemoglobin protein.

A chain made of more than 50 amino acids is usually referred to as a(n)

Zwitterions have an overall positive charge.

Heavy metals denature proteins by

The interactions that are important in the secondary structure of a protein are

Hemoglobin is an example of a protein with

The secondary structure of collagen is distinguished by

Disulfide bonds in a protein chain connect

Which of the following shows all of the tripeptides that can be formed from one molecule each of lysine (Lys), threonine (Thr), and histidine (His)?

Sucrase, the protein that facilitates the hydrolysis of sucrose, would be classified as a __________ protein.

Amino acids that are not synthesized in the body but must be ingested with the diet are called __________ amino acids.

The following amino acid R group chain is

A zwitterion of any amino acid has a net charge of __________.

Glycine is the only naturally occurring amino acid that is

Classify each protein by function. -

In the peptide Ala-Try-Gly-Phe, the N-terminal amino acid is

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