Question 1

How many amino acids have basic side chains?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
A)  1 
B)  2 
C)  3 
D)  4

Question 2

The denaturing agent urea affects which of the following?

Accepted Answer

A)  hydrogen bonding 
B)  disulfide bonds 
C)  hydrophobic interactions 
D)  salt bridges 
A)  hydrogen bonding 
B)  disulfide bonds 
C)  hydrophobic interactions 
D)  salt bridges

Question 3

Which of the following amino acids absorbs UV radiation at 280 nm?

Accepted Answer

A)  phenylalanine 
B)  tryptophan 
C)  tyrosine 
D)  all of these 
A)  phenylalanine 
B)  tryptophan 
C)  tyrosine 
D)  all of these

Question 4

Which type of secondary structure can be either intermolecular or intramolecular?

Accepted Answer

A)  α-helix 
B)  β-pleated sheet 
C)  hairpin turn 
D)  all of these 
A)  α-helix 
B)  β-pleated sheet 
C)  hairpin turn 
D)  all of these

Question 5

Which of the following side chains are hydrophobic?

Accepted Answer

A)  acidic 
B)  basic 
C)  polar but neutral 
D)  none of these 
A)  acidic 
B)  basic 
C)  polar but neutral 
D)  none of these

Question 6

Serotonin is formed from which amino acid?

Accepted Answer

A)  phenylalanine 
B)  tryptophan 
C)  tyrosine 
D)  valine 
A)  phenylalanine 
B)  tryptophan 
C)  tyrosine 
D)  valine

Question 7

How many different amino acids are commonly found in proteins?

Accepted Answer

A)  10 
B)  20 
C)  200 
D)  1000 
A)  10 
B)  20 
C)  200 
D)  1000

Question 8

What determines the characteristics of an amino acid?

Accepted Answer

A)  its molecular weight 
B)  the identity of its side chain 
C)  both a and b 
D)  neither a nor b 
A)  its molecular weight 
B)  the identity of its side chain 
C)  both a and b 
D)  neither a nor b

Question 9

Which of the following is true of an amino acid at a pH above its isoelectric point?

Accepted Answer

A)  It will have a negative charge. 
B)  It will be electrically neutral. 
C)  It will have a positive charge. 
D)  We cannot predict its charge. 
A)  It will have a negative charge. 
B)  It will be electrically neutral. 
C)  It will have a positive charge. 
D)  We cannot predict its charge.

Question 10

The substance shown below is called cisplatin and is used in the treatment of testicular cancer. [Pt(NH3)2Cl2]
What is the oxidation state of Pt in this substance?

Accepted Answer

A)  0 
B)  +1 
C)  +2 
D)  +3 
E)  +4 
A)  0 
B)  +1 
C)  +2 
D)  +3 
E)  +4

Question 11

Which of the following is associated with the quaternary structure of proteins?

Accepted Answer

A)  the sequence of amino acids 
B)  hydrogen bonding within the backbone 
C)  hydrogen bonding between the side chains 
D)  the interaction of protein subunits 
A)  the sequence of amino acids 
B)  hydrogen bonding within the backbone 
C)  hydrogen bonding between the side chains 
D)  the interaction of protein subunits

Question 12

Which of the following is true of the isoelectric point of amino acids?

Accepted Answer

A)  The isoelectric points of all amino acids are the same. 
B)  It is the pH at which an amino acid conducts electricity. 
C)  It is the pH at which an amino acid has equal numbers of positive and negative charges. 
D)  All of the above are true. 
A)  The isoelectric points of all amino acids are the same. 
B)  It is the pH at which an amino acid conducts electricity. 
C)  It is the pH at which an amino acid has equal numbers of positive and negative charges. 
D)  All of the above are true.

Question 13

Which of the following explains the unusually high melting points of amino acids?

Accepted Answer

A)  their formula weights 
B)  the polarity of the side chains 
C)  the presence of nitrogen atoms 
D)  their existence as zwitterions 
A)  their formula weights 
B)  the polarity of the side chains 
C)  the presence of nitrogen atoms 
D)  their existence as zwitterions

Question 14

In which of the following do both amino acids have a nonpolar side chain?

Accepted Answer

A)  cysteine and glycine 
B)  cysteine and methionine 
C)  histidine and methionine 
D)  phenylalanine and tryptophan 
A)  cysteine and glycine 
B)  cysteine and methionine 
C)  histidine and methionine 
D)  phenylalanine and tryptophan

Question 15

What type of chemical reaction is involved in the conversion of cystine to cysteine?

Accepted Answer

A)  addition 
B)  reduction 
C)  oxidation 
D)  substitution 
A)  addition 
B)  reduction 
C)  oxidation 
D)  substitution

Question 16

Which of the following is not a fibrous protein?

Accepted Answer

A)  actin 
B)  collagen 
C)  keratin 
D)  None, they are all fibrous proteins. 
A)  actin 
B)  collagen 
C)  keratin 
D)  None, they are all fibrous proteins.

Question 17

In which of the following do both amino acids have a polar but neutral side chain?

Accepted Answer

A)  cysteine and methionine 
B)  cysteine and serine 
C)  histidine and methionine 
D)  phenylalanine and tryptophan 
A)  cysteine and methionine 
B)  cysteine and serine 
C)  histidine and methionine 
D)  phenylalanine and tryptophan

Question 18

Which of the following amino acids has the lowest pI?

Accepted Answer

A)  arginine 
B)  cysteine 
C)  glycine 
D)  glutamic acid 
A)  arginine 
B)  cysteine 
C)  glycine 
D)  glutamic acid

Question 19

Which of the following is a type of secondary structure?

Accepted Answer

A)  α-pleated sheet 
B)  β-helix 
C)  both a and b 
D)  neither a nor b 
A)  α-pleated sheet 
B)  β-helix 
C)  both a and b 
D)  neither a nor b

Question 20

Using the 20 standard amino acids how many dipeptides containing two different amino acids can be made?

Accepted Answer

A)  20 
B)  39 
C)  40 
D)  380 
A)  20 
B)  39 
C)  40 
D)  380

Exam 22: Proteins

How many amino acids have basic side chains?

The denaturing agent urea affects which of the following?

Which of the following amino acids absorbs UV radiation at 280 nm?

Which type of secondary structure can be either intermolecular or intramolecular?

Which of the following side chains are hydrophobic?

Serotonin is formed from which amino acid?

How many different amino acids are commonly found in proteins?

What determines the characteristics of an amino acid?

Which of the following is true of an amino acid at a pH above its isoelectric point?

The substance shown below is called cisplatin and is used in the treatment of testicular cancer. [Pt(NH3)2Cl2] What is the oxidation state of Pt in this substance?

Which of the following is associated with the quaternary structure of proteins?

Which of the following is true of the isoelectric point of amino acids?

Which of the following explains the unusually high melting points of amino acids?

In which of the following do both amino acids have a nonpolar side chain?

What type of chemical reaction is involved in the conversion of cystine to cysteine?

Which of the following is not a fibrous protein?

In which of the following do both amino acids have a polar but neutral side chain?

Which of the following amino acids has the lowest pI?

Which of the following is a type of secondary structure?

Using the 20 standard amino acids how many dipeptides containing two different amino acids can be made?

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The substance shown below is called cisplatin and is used in the treatment of testicular cancer. [Pt(NH₃)₂Cl₂] What is the oxidation state of Pt in this substance?