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PROTEINS AND PROTEIN METABOLISM- Part 8
See all quizzes of PROTEINS AND PROTEIN METABOLISM- Part 8 here:
1. Hydroxylation of phenylalanine requires
all of the following except
(A) Phenylalanine hydroxylase
(B) Tetrahydrobiopterin
(C) NADH
(D) Molecular oxygen
2. Non-Protein amino acids are
(A) Ornithine
(B) β-alanine
(C) γ-amino butyric acid
(D) All of these
3. The amino acid that undergoes oxidative
deamination at significant rate is
(A) Alanine (B) Aspartate
(C) Glutamate (D) Glutamine
4. Allosteric inhibitor of glutamate dehydrogenase
is
(A) ATP (B) ADP
(C) AMP (D) GMP
PROTEINS AND PROTEIN METABOLISM 39
5. Allsoteric activator of glutamate dehydrogenase
is
(A) ATP (B) GTP
(C) ADP and GDP (D) AMP and GMP
6. Free ammonia is released during
(A) Oxidative deamination of glutamate
(B) Catabolism of purines
(C) Catabolism of pyrimidines
(D) All of these
7. An organ which is extremely sensitive to
ammonia toxicity is
(A) Liver (B) Brain
(C) Kidney (D) Heart
8. Ammonia is transported from muscles to
liver mainly in the form of
(A) Free ammonia (B) Glutamine
(C) Asparagine (C) Alanine
9. The major site of urea synthesis is
(A) Brain (B) Kidneys
(C) Liver (D) Muscles
10. Carbamoyl phosphate required for urea
synthesis is formed in
(A) Cytosol (B) Mitochondria
(C) Both (A) and (B) (D) None of these
11. Cytosolic and mitochondrial carbamoyl
phosphate synthetase have the following
similarity:
(A) Both use ammonia as a substance
(B) Both provide carbamoyl phosphate for urea
synthesis
(C) Both require N-acetylglutamate as an
activator
(D) Both are allosteric enzymes
12. The following enzyme of urea cycle is
present in cytosol:
(A) Argininosuccinic acid synthetase
(B) Argininosuccinase
(C) Arginase
(D) All of these
13. ATP is required in following reactions of
urea cycle:
(A) Synthesis of carbamoyl phosphate and
citrulline
(B) Synthesis of citrulline and argininosuccinate
(C) Synthesis of argininosuccinate and arginine
(D) Synthesis of carbamoyl phosphate and
argininosuccinate
14. Daily excretion of nitrogen by an adult
man is about
(A) 15–20 mg (B) 1.5–2 gm
(C) 5–10 gm (D) 15–20 gm
15. Maple syrup urine diseases is an inborn
error of metabolism of
(A) Sulphur-containing amino acids
(B) Aromatic amino acids
(C) Branched chain amino acids
(D) Dicarboxylic amino acids
16. Cystinuria results from inability to
(A) Metabolise cysteine
(B) Convert cystine into cysteine
(C) Incorporate cysteine into proteins
(D) Reabsorb cystine in renal tubules
17. The defective enzyme in histidinemia is
(A) Histidine carboxylase
(B) Histidine decarboxylase
(C) Histidase
(D) Histidine oxidase
18. All the following statements about
phenylketonuria are correct except
(A) Phenylalanine cannot be converted into
tyrosine
(B) Urinary excretion of phenylpyruvate and
phenyllactate is increased
(C) It can be controlled by giving a lowphenylalanine
diet
(D) It leads to decreased synthesis of thyroid
hormones, catecholamines and melanin
19. All the following statements about
albinism are correct except
(A) Tyrosine hydroxylase (tyrosinase) is absent or
deficient in melanocytes
(B) Skin is hypopigmented
(C) It results in mental retardation
(D) Eyes are hypopigmented
20. Glycine is not required for the formation
of
(A) Taurocholic acid (B) Creatine
(C) Purines (D) Pyrimidines
21. Histamine is formed from histidine by
(A) Deamination (B) Dehydrogenation
(C) Decarboxylation (D) Carboxylation
22. DOPA is an intermediate in the synthesis
of
(A) Thyroid hormones
(B) Catecholamines
(C) Melanin
(D) Catecholamines and melanin
23. All the following statements about pepsin
are correct except
(A) It is smaller than pepsinogen
(B) It is formed by the action of HCl on its precursor
(C) Its optimum pH is 1.0–2.0
(D) It hydrolyses the C-terminal and N-terminal
peptide bonds of proteins
24. Pancreatic juice contains the precursors of
all of the following except
(A) Trypsin (B) Chymotrypsin
(C) Carboxypeptidase (D) Aminopeptidase
25. The only correct statement about chymotrypsin
is
(A) It is formed from trypsin
(B) Carboxypeptidase converts trypsin into
chymotrypsin
(C) Its optimum pH is around 7
(D) It hydrolyses peptide bonds involving basic
amino acids
26. The portion of the antigen molecule which
is recognized by antibody is known as
(A) Hapten (B) Epitope
(C) Complement (D) Variable region
27. All the following statements about
haptens are true except
(A) They have high molecular weights
(B) They cannot elicit an immune response by
themselves
(C) When combined with some other large
molecule, they can elicit an immune response
(D) Once an immune response develops, the free
hapten can be recognized by the antibody
28. Antigens and haptens have the following
similarity:
(A) They have high molecular weights
(B) They can elicit immune response by themselves
(C) They can elicit an immune response only in
association with some other large molecule
(D) Once an immune response develops, free
antigen and free hapten can be recognized
by the antibody
29. The minimum number of polypeptide
chains in an immunoglobulin is
(A) Two (B) Four
(C) Five (D) Six
30. Light chains of immunoglobulins are of
following types:
(A) Alpha and kappa (B) Alpha and gamma
(C) Lambda and delta(D) Kappa and lambda
