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Essential Biochemistry - Protein Metabolism (Section 2)

1
What is the fate of the carbon skeleton of glucogenic amino acids?
Answer
(B)
Converted to glucose or glycogen.
2
Which of the following compounds is the immediate precursor of dopamine?
Answer
(B)
DOPA
3
Which of the following amino acids can be converted to pyruvate?
Answer
A
B
C
D
4
Which of the following amino acids are essential for the synthesis of cysteine?
Answer
A
B
5
What compound is a product of the degradation of tyrosine?
Answer
(B)
Fumarate
6
What is the primary role of melatonin?
Answer
(A)
Regulation of the sleep-wake cycle
7
Which enzyme deficiency is associated with tyrosinemia type I?
Answer
(A)
Fumarylacetoacetate hydrolase
8
Which of the following compound(s) can be generated from tryptophan?
Answer
A
B
C
9
What compound does glutamine degrade into?
Answer
(A)
Glutamate
10
Which amino acid can be synthesized in the body from methionine?
Answer
(A)
Cysteine
11
Which amino acids are considered glucogenic?
Answer
C
D
12
What is the daily protein requirement for an adult?
Answer
(A)
50-60 g
13
What is the role of aspartate in the urea cycle?
Answer
(B)
It donates an amino group to form urea.
14
Which amino acids can be directly converted to pyruvate?
Answer
A
B
C
15
What is the primary role of the kidneys in amino acid metabolism?
Answer
(C)
Ammonia excretion
16
What is the key molecule that regulates melanin synthesis?
Answer
(B)
Tyrosinase
17
Which coenzyme is used in transamination reactions?
Answer
(B)
Pyridoxal phosphate
18
Which of the following are the main end products of protein digestion?
Answer
(B)
Amino acids, dipeptides, and tripeptides
19
What are the primary functions of amino acids?
Answer
A
C
D
20
Which of the following is the result of the degradation of threonine?
Answer
A
C
D
21
The fate of ammonia in brain is:
Answer
(B)
Conversion to glutamate
22
Which amino acid is used in the synthesis of carnitine?
Answer
(A)
Lysine
23
Which of the following compounds are formed from phenylalanine and tyrosine?
Answer
A
B
24
Homocystinuria is due to a deficiency in which enzyme?
Answer
(A)
Cystathionine beta-synthase
25
Which of the following enzymes is involved in the first committed step of the urea cycle?
Answer
(B)
Carbamoyl phosphate synthetase I
26
Cysteine is a precursor for the synthesis of:
Answer
(A)
Glutathione and taurine
27
Which of the following does not take part in the human urea cycle?
Answer
(D)
Urease
28
Which of the following is/are essential amino acids?
Answer
B
C
29
Which of the following is a precursor for the synthesis of creatine?
Answer
(D)
All of the above
30
What is the primary product of the urea cycle?
Answer
(B)
Urea
31
In which cellular compartment does the urea cycle begin?
Answer
(B)
Mitochondria
32
Which condition is characterized by an increase in glycine in the blood and urine?
Answer
(C)
Glycinuria
33
Which coenzyme is required for transamination reactions?
Answer
(B)
Pyridoxal phosphate (PLP)
34
What is the primary function of the liver in amino acid metabolism?
Answer
(D)
All of the above.
35
The amino acid required for synthesis of heme is:
Answer
(C)
Glycine
36
What is the inactive precursor of pepsin?
Answer
(B)
Pepsinogen
37
All of the following are synthesized from tyrosine, except:
Answer
(B)
Serotonin
38
Cystinuria is primarily caused by:
Answer
(B)
Impaired absorption of cysteine in the kidneys
39
What type of amino acids can be used to synthesize glucose?
Answer
(B)
Glucogenic amino acids
40
Which amino acid is used in the formation of creatine?
Answer
(A)
Arginine
41
Which of the following is NOT a characteristic of maple syrup urine disease?
Answer
(D)
Excessive levels of cystine in the blood
42
What is the function of transaminases in amino acid metabolism?
Answer
(B)
To transfer amino groups between amino acids and keto acids.
43
Which amino acid is converted to pyruvate by a single enzymatic step?
Answer
(A)
Alanine
44
Where does the urea cycle occur in the cell?
Answer
(C)
Both mitochondria and cytosol
45
Which amino acid is degraded to alpha-ketoglutarate?
Answer
(D)
All of the above
46
What type of nitrogen balance is observed in growing children?
Answer
(C)
Positive nitrogen balance
47
Which enzyme is primarily responsible for protein digestion in the stomach?
Answer
(B)
Pepsin
48
Which of the following is a symptom of alkaptonuria?
Answer
(A)
Dark urine upon standing
49
Which of the following enzymes is involved in the synthesis of carbamoyl phosphate?
Answer
(B)
Carbamoyl phosphate synthetase I
50
Which of the following is an essential amino acid?
Answer
(B)
Methionine