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Quick Biochemistry - Proteins And Protein Metabolism (Section 1)

1
What is a universal component found in all proteins?
Answer
(A)
A consistent set of 20 amino acids
2
What type of amino acids are typically found in proteins?
Answer
(A)
Primarily L-α-amino acids
3
Which amino acid does not exhibit optical activity?
Answer
(A)
Glycine
4
In a neutral pH environment, what is the primary form of amino acids in a solution?
Answer
(A)
Zwitterions
5
Which statement accurately describes the behavior of amino acids in a solution at a typical biological pH?
Answer
(A)
All amino acids carry both positive and negative charges
6
What is the isoelectric point (pI) of alanine?
Answer
(A)
6.02
7
Aspartic acid has pK values of 2.0, 3.9, and 10.0. What would be its isoelectric point (pH)?
Answer
(A)
3.0
8
Which of the following amino acids contains sulfur?
Answer
(A)
Methionine
9
Which option presents an example of an amino acid with a sulfur component?
Answer
(A)
2-Amino-3-mercaptopropanoic acid
10
Which of the listed amino acids is NOT a sulfur-containing amino acid commonly found in proteins?
Answer
(D)
Threonine
11
Which of the following amino acids is aromatic?
Answer
(B)
Tyrosine
12
What are the roles of plasma albumin?
Answer
(D)
Both osmotic balance and transport
13
Which amino acid has a side chain containing basic functional groups?
Answer
(A)
2-Amino 5-guanidovaleric acid
14
Which of these is an a-amino acid that is not found in proteins but is important for metabolism in mammals?
Answer
(C)
2-Amino 4-mercaptobutanoic acid
15
Which amino acid is necessary in the human diet?
Answer
(C)
Methionine
16
What is true regarding non-essential amino acids?
Answer
(B)
They can be produced by the body from essential amino acids.
17
Which of these amino acids is considered conditionally essential for humans?
Answer
(B)
Arginine
18
Which of the following is an example of a polar amino acid?
Answer
(C)
Arginine
19
Which amino acid has a nonpolar side chain?
Answer
(B)
Valine
20
Which amino acid can be broken down to produce ketone bodies?
Answer
(C)
Leucine
21
Which amino acid typically disrupts alpha-helical structures?
Answer
(B)
Proline
22
Which of the following amino acids is typically not found in proteins?
Answer
(A)
β-Alanine
23
Which amino acid can serve as a precursor for glycine in mammalian tissues?
Answer
(B)
Glycine
24
A vasodilator is produced by removing a carboxyl group from which amino acid?
Answer
(D)
Histidine
25
The Biuret test specifically detects what type of chemical bond?
Answer
(A)
-CONH-linkages
26
Which amino acid is specifically identified by the Sakaguchi reaction?
Answer
(C)
Arginine
27
Which amino acid reacts specifically in the Million-Nasse reaction?
Answer
(B)
Tyrosine
28
Ninhydrin reacts with which compound to produce a blue color and release CO₂?
Answer
(B)
α-Amino acids
29
The majority of the UV light absorption in proteins above 240 nm is due to the presence of which amino acid?
Answer
(A)
Tryptophan
30
Which of the following is composed of two amino acids linked together?
Answer
(A)
Anserine
31
Which of the following is composed of three amino acids bonded together?
Answer
(C)
Glutathione
32
What is a peptide known for its ability to lower blood pressure in smooth muscle?
Answer
(B)
Bradykinin
33
What tripeptide serves as a key reducing agent within biological tissues?
Answer
(D)
Glutathione
34
Which of the following is a protein that incorporates a metal ion?
Answer
(B)
Ceruloplasmin
35
What type of protein does carbonic anhydrase exemplify?
Answer
(C)
Metalloprotein
36
What substance is a protein that contains a pigment?
Answer
(A)
Hemoglobin
37
Which of these is a structural protein found in animals?
Answer
(B)
Keratin
38
What type of protein is casein, a component of milk?
Answer
(C)
Phosphoprotein
39
What is a phosphoprotein found within egg yolk?
Answer
(C)
Ovovitellin
40
Which of the following is a basic protein found in the nucleus of sperm cells?
Answer
(B)
Protamine
41
What are histones best described as?
Answer
(B)
Proteins containing a high concentration of lysine and arginine
42
What is the primary protein found in hair?
Answer
(A)
Keratin
43
Which amino acid is primarily involved in the creation of hair keratin?
Answer
(B)
Methionine
44
Approximately how many amino acids are in a single albumin molecule?
Answer
(C)
610
45
Which type of plasma protein has a hexosamine content exceeding 4%?
Answer
(C)
Mucoproteins
46
After oxygen delivery to tissues, what does hemoglobin primarily carry?
Answer
(A)
CO₂ and protons to the lungs
47
Ehlers-Danlos syndrome, characterized by flexible joints and skin issues, often results from
Answer
(A)
A genetic issue related to procollagen
48
In what solvent do proteins typically dissolve?
Answer
(B)
Aqueous alcohol
49
Which cereal protein dissolves in 70% alcohol but not in water or salt solutions?
Answer
(D)
Gliadin
50
Globular proteins often maintain stability in solution despite the absence of
Answer
(A)
Disulphide bonds