Essential Biochemistry - Protein Metabolism (Section 11)
1
What is the importance of the saccharopine pathway?
2
What is the form of ammonia primarily transported in the bloodstream?
3
Which of the following can form pyruvate?
4
Which enzyme is crucial for activating trypsinogen?
5
The reactions of urea cycle occur in:
6
Which condition is characterized by a positive nitrogen balance?
7
Which of the following amino acids are exclusively ketogenic?
8
The amino acid required for synthesis of heme is:
9
All of the following are synthesized from tyrosine, except:
10
What is a characteristic feature of the clinical presentation of cystinuria?
Svar(B)
Formation of kidney stones
11
Which enzyme is directly involved in the formation of urea?
12
Which amino acid is the immediate precursor for the synthesis of GABA (gamma-aminobutyric acid)?
13
Which of the following amino acids is a precursor for the synthesis of epinephrine and norepinephrine?
14
Which enzyme catalyzes the first step in the biosynthesis of melanin?
15
Which of the following processes does NOT require tetrahydrofolate (THF)?
16
Which enzyme is vital for activating trypsinogen into trypsin?
17
The following enzymes are involved in digestion and absorption of protein, except:
18
What is the key role of glutathione in cells?
19
Which of the following is/are formed from the catabolism of carbon skeletons of amino acids?
20
Which of the following statements is correct regarding the role of serine hydroxymethyltransferase?
21
Which of the following amino acids is degraded to yield acetyl-CoA?
22
Which of the following amino acids can be converted into pyruvate?
23
What is the cause of phenylketonuria (PKU)?
Svar(B)
Deficiency of phenylalanine hydroxylase
24
Which of the following amino acids is metabolized via the kynurenine pathway?
25
Which of the following amino acids is a substrate in the formation of ornithine?
26
Where does the first step of the urea cycle take place?
27
Which enzyme is responsible for the activation of trypsinogen in the small intestine?
28
Which of the following is the main function of the urea cycle?
29
Which of the following is NOT a characteristic of phenylketonuria (PKU)?
Svar(D)
Excessive production of tyrosine
30
Which of the following are classified as exclusively ketogenic amino acids?
31
Which substance is responsible for activating pepsinogen into pepsin?
32
What activates the zymogen pepsinogen?
33
What is the role of SAM (S-adenosylmethionine) in methionine metabolism?
Svar(B)
Serves as a methyl group donor
34
Which amino acid is a substrate for the synthesis of proline?
35
Which of the following amino acids is NOT glucogenic?
36
What enzyme converts glutamate to glutamine?
37
Which metabolic defect causes maple syrup urine disease?
Svar(B)
Defect in branched-chain amino acid metabolism
38
What is the key enzyme involved in the urea cycle?
39
What is the main function of glutamine in the kidney?
40
Where is most protein digested and absorbed in the body?
41
What activates pepsinogen?
42
What is the main function of the small intestine in protein digestion?
43
Which of the following molecules is primarily transported in the blood as a method of carrying nitrogen?
44
What is the main function of histamine in the body?
Svar(C)
Immune response and inflammation
45
Which of the following are branched-chain amino acids?
46
Which intermediate plays a key role in the urea cycle?
47
What is the key metabolic pathway for the degradation of lysine?
48
Which amino acids are utilized in the synthesis of creatine?
49
Which amino acid is the primary transport form of ammonia in the blood?
50
Which of the following are intermediates in the urea cycle?
