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Essential Biochemistry - Chemistry Of Proteins (Section 2)

1
Which amino acid is responsible for forming disulfide bonds?
Answer
(B)
Cysteine
2
What type of interaction is primarily responsible for the formation of alpha-helices and beta-sheets in proteins?
Answer
(B)
Hydrogen bonds
3
What type of reaction joins amino acids together to form a polypeptide chain?
Answer
(B)
Dehydration synthesis
4
Which of the following amino acids contains sulfur?
Answer
(C)
Cysteine
5
Which of the following is true regarding the alpha-helix?
Answer
(C)
It is a coiled structure held together by hydrogen bonds
6
What is the role of a signal peptide?
Answer
(C)
To direct a protein to a specific cellular location.
7
Which of the following is a characteristic of an alpha-helix?
Answer
(C)
It is a spiral structure stabilized by hydrogen bonds.
8
Which of the following amino acid is exclusively ketogenic?
Answer
(A)
Leucine
9
Which amino acid side chain is most likely to participate in hydrogen bonding?
Answer
(C)
Serine
10
Which amino acid is often involved in the stabilization of protein structure due to its ability to form disulfide bonds?
Answer
(B)
Cysteine
11
What type of interactions primarily stabilize the secondary structure of a protein?
Answer
(B)
Hydrogen bonds
12
What is the quaternary structure of a protein?
Answer
(D)
The arrangement of multiple polypeptide chains
13
What is the isoelectric point (pI) of a protein?
Answer
(D)
The pH at which the protein has a net charge of zero
14
The secondary structure of protein is stabilized by:
Answer
(A)
Hydrogen bonds
15
Which amino acids are classified as acidic amino acids?
Answer
A
B
16
What does it mean for an amino acid to be "essential"?
Answer
(C)
It must be obtained from the diet
17
Which amino acid is a precursor for the synthesis of melanin?
Answer
(B)
Tyrosine
18
All of the following forces may play a role in the formation of tertiary structure, except
Answer
(D)
Peptide bonds
19
Which of the following is an example of a structural protein?
Answer
(C)
Collagen
20
Which class of amino acids contain only non-essential amino acids?
Answer
(B)
Acidic
21
Which of the following is a characteristic of a beta-sheet?
Answer
(B)
It is formed by hydrogen bonds between strands of the polypeptide
22
Which level of protein structure refers to the interactions between different polypeptide subunits?
Answer
(D)
Quaternary
23
Which of the following is an example of a storage protein?
Answer
(C)
Ferritin
24
Which of the following amino acids is classified as a basic amino acid?
Answer
(C)
Arginine
25
What are some of the main functions of proteins in the body?
Answer
A
B
C
D
26
What are some properties of amino acids?
Answer
A
B
C
27
Which of the following is an essential amino acid?
Answer
(C)
Leucine
28
What type of bond is formed between two cysteine residues in a protein?
Answer
(B)
Disulfide bond
29
What type of protein is an antibody?
Answer
(C)
Defense protein
30
Which of the following is NOT a type of non-covalent interaction that stabilizes protein structure?
Answer
(D)
Peptide bonds
31
What type of protein is responsible for transporting oxygen in the blood?
Answer
(C)
Hemoglobin
32
What is the role of the R-group (side chain) of an amino acid?
Answer
(B)
To determine the properties of the amino acid
33
Which of the following amino acids does NOT have a chiral alpha carbon?
Answer
(B)
Glycine
34
Which of the following are examples of modified or nonstandard amino acids?
Answer
A
B
35
Which of the following is a function of proteins?
Answer
A
B
C
D
36
Which of the following amino acids has a positively charged side chain at physiological pH?
Answer
(C)
Lysine
37
All amino acids found in proteins are optically active, except
Answer
(B)
Glycine
38
Which of the following is a nonpolar amino acid?
Answer
(C)
Valine
39
In humans all of the following amino acids are essential, except
Answer
(B)
Glycine
40
Which of the following can cause denaturation of proteins?
Answer
A
B
C
41
Which amino acid plays a key role in forming the active site of many enzymes due to its ability to donate or accept protons?
Answer
(C)
Histidine
42
Which of the following is a basic amino acid?
Answer
(C)
Lysine
43
Which of the following amino acids is least likely to be found in an alpha-helix?
Answer
(B)
Glycine
44
Proteins are classified based on their functions. What are some examples of proteins grouped by function?
Answer
A
B
C
D
45
Glycine is used for synthesis of the following, except:
Answer
(C)
Proline
46
Which of the following is a characteristic of an amphipathic amino acid?
Answer
(C)
It has both hydrophobic and hydrophilic regions.
47
Which of the following amino acids is nonpolar?
Answer
(C)
Alanine
48
Which of the following functional groups is found in all amino acids?
Answer
(A)
-COOH
49
What type of secondary structure is characterized by a coiled, spring-like shape?
Answer
(B)
Alpha-helix
50
What type of interactions are primarily responsible for hydrophobic interactions in protein folding?
Answer
(B)
Van der Waals forces