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Essential Biochemistry - Protein Metabolism (Section 7)

1
Which region is primarily where the absorption of digested proteins happens?
Answer
(C)
Jejunum
2
Which amino acid is the precursor for the synthesis of catecholamines?
Answer
(B)
Tyrosine
3
What is the primary role of ornithine in the urea cycle?
Answer
(A)
Accepting a carbamoyl group
4
Which of the following is primarily used in the synthesis of collagen?
Answer
(D)
All of the above
5
Which enzyme is involved in the degradation of tryptophan?
Answer
(B)
Tryptophan dioxygenase
6
Which type of reaction is conversion of norepinephrine to epinephrine?
Answer
(C)
Transmethylation
7
What is the primary function of transamination?
Answer
(B)
Transferring amino groups between amino acids.
8
Which of the following statements are true regarding the role of serotonin in humans?
Answer
A
B
C
9
Which of these is a product of the Urea cycle?
Answer
A
B
10
What is the source of the nitrogen in urea?
Answer
(A)
Ammonia and aspartate
11
Which action is characteristic of transamination reactions?
Answer
(B)
Amino group transfer
12
What is the main function of the urea cycle in the body?
Answer
(B)
Ammonia detoxification
13
Which amino acid is involved in the formation of proline?
Answer
(A)
Glycine
14
Which of the following amino acids are exclusively ketogenic?
Answer
A
B
15
Which amino acid is involved in the synthesis of urea?
Answer
(B)
Aspartate
16
What is the role of the methyl group provided by 5-methyl-tetrahydrofolate (5-methyl-THF)?
Answer
(C)
Conversion of homocysteine to methionine
17
What is the general function of transaminases?
Answer
(C)
To transfer amino groups.
18
Which of the following amino acids is a substrate for the synthesis of urea?
Answer
(B)
Aspartate
19
What process does deamination perform on amino acids?
Answer
(B)
Removes amino groups
20
Which amino acid is the precursor of epinephrine?
Answer
(C)
Tyrosine
21
What defines the deamination process of amino acids?
Answer
(B)
Amino group removal
22
Which of the following is a key substrate used in the production of purines?
Answer
(D)
All of the above
23
What is the role of arginase in the urea cycle?
Answer
(C)
To produce urea
24
What is the primary role of HCl in gastric protein digestion?
Answer
(C)
Denaturing proteins
25
In what organ does the urea cycle primarily occur?
Answer
(B)
Liver
26
What is the role of HCl in protein digestion in the stomach?
Answer
(B)
Denature proteins
27
Which of the following is a characteristic of the degradation of branched-chain amino acids?
Answer
(C)
They involve the formation of ketone bodies.
28
Which enzyme is responsible for the activation of trypsin?
Answer
(B)
Enteropeptidase
29
Which of the following are important for the formation of glutathione?
Answer
A
B
C
30
Which of the following is a characteristic of the urea cycle?
Answer
(B)
It produces urea.
31
Which of the following molecules participate directly in urea synthesis?
Answer
A
B
C
32
Which enzyme is deficient in the genetic disorder albinism?
Answer
(B)
Tyrosinase
33
What is the role of pepsin in protein digestion?
Answer
(B)
Hydrolyzing proteins into smaller peptides
34
Which amino acid deficiency is associated with Hartnup disease?
Answer
(A)
Tryptophan
35
Which of the following is NOT directly produced from pyruvate?
Answer
(C)
Glycine
36
Which enzyme is deficient in phenylketonuria?
Answer
(A)
Phenylalanine hydroxylase
37
What is the term for the process by which the amino group is removed from an amino acid?
Answer
(B)
Deamination
38
Which cofactor is important in the hydroxylation of phenylalanine?
Answer
(C)
BH4
39
What is the first committed step in pyrimidine synthesis?
Answer
(B)
Carbamoyl phosphate synthetase II (CPS II)
40
Which of the following is/are products of the complete catabolism of amino acids?
Answer
A
B
C
D
41
What enzyme is deficient in classic homocystinuria?
Answer
(B)
Cystathionine beta-synthase
42
What is the function of HCl in gastric digestion?
Answer
(C)
Denature proteins
43
Which enzyme catalyzes the formation of urea?
Answer
(C)
Carbamoyl phosphate synthetase I
44
Transamination of oxaloacetate results in the formation of:
Answer
(A)
Aspartic acid
45
Which of the following amino acids are nutritionally essential?
Answer
A
C
46
Which of the following amino acids are essential?
Answer
A
B
C
47
What is the role of trypsin in protein digestion?
Answer
(B)
Activates other zymogens
48
Which is a key player in the urea cycle?
Answer
(B)
Ammonia
49
Which is a characteristic of a negative nitrogen balance?
Answer
(B)
Protein breakdown exceeds protein synthesis
50
What is the primary function of the urea cycle in the body?
Answer
(B)
Detoxify ammonia