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NUCLEIC ACIDS- Part 20
See all quizzes of NUCLEIC ACIDS- Part 20 here:
1 A common substrate of HGPRTase, APRTase
and PRPP glutamyl amidotransferase is
(A) Ribose 5 phosphate
(B) Phosphoribosyl pyrophosphate
(C) Hypoxanthine
(D) Adenosine
2. Carbon 6-of purine skeleton comes from
(A) Atmospheric CO2
(B) 1 carbon carried by folate
(C) Betoine
(D) Methionine
3. Uric acid is the catabolic end product of
(A) Porphyrine (B) Purines
(C) Pyrimidines (D) Pyridoxine
4. Diphenylamine method is employed in the
quantitation of
(A) Nucleic acid (B) RNA
(C) DNA (D) Proteins
5. Orcinol method is employed in the quantitation
of
(A) Nucleic acid (B) DNA
(C) RNA (D) Proteins
6. Nucleic acid show strong absorption at
one of the wavelength:
(A) 280 nm (B) 220 nm
(C) 360 nm (D) 260 nm
7. tRNA has
(A) Clover leaf structure
(B) anticodon arm
(C) poly ‘A’ tay 3’
(D) Cap at 5’ end
8. Which one of the following contributes
nitrogen atoms to both purine and
pyrimidine rings?
(A) Aspartate
(B) Carbanoyl phosphate
(C) Carbondioxide
(D) Tetrahydrofolate
9. The four nitrogen atoms of purines are
derived from
(A) Urea and NH3
(B) NH3, Glycine and Glutamate
(C) NH3, Asparate and Glutamate
(D) Aspartate, Glutamine and Glycine
10. A drug which prevents uric acid synthesis
by inhibiting the enzyme Xanthine oxidase
is
(A) Aspirin (B) Allopurinal
(C) Colchicine (D) Phenyl benzoate
11. Glycine contributes to the following C and
N of purine nucleus:
(A) C1, C2 and N7 (B) C8, C8 and N9
(C) C4, C5 and N7 (D) C4, C5 and N9
12. Insoinic acid is the biological precursor of
(A) Cytosine and Uric acid
(B) Adenylve acid and Glucine floc acid
(C) Orotic acid and Uridylic acid
(D) Adenosine acid Thymidine
13. The probable metabolic defect in gents is
(A) A defect in excretion of uric acid by kidney
(B) An overproduction of pyrimidines
(C) An overproduction of uric acid
(D) Rise in calcium leading to deposition of calcium
urate
14. In humans, the principal break down
product of purines is
(A) NH3 (B) Allantin
(C) Alanine (D) Uric acid
15. A key substance in the committed step of
pyrimidines biosynthesis is
(A) Ribose-5-phosphate
(B) Carbamoyl phosphate
(C) ATP
(D) Glutamine
16. In humans, the principal metabolic
product of pyrimidines is
(A) Uric acid (B) Allantoin
(C) Hypoxanthine (D) β-alanine
17. In most mammals, except primates, uric
acid is metabolized by
(A) Oxidation to allantoin
(B) Reduction to NH3
(C) Hydrolysis to allantoin
(D) Hydrolysis to NH3
18. Two nitrogen of the pyrimidines ring are
obtained from
(A) Glutamine and Carbamoyl-p
(B) Asparate and Carbamoyl-p
(C) Glutamate and NH3
(D) Glutamine and NH3
19. All are true about lesch-nyhan syndrome
except
(A) Produces self-mutilation
(B) Genetic deficiency of the enzyme
(C) Elevated levels of uric acid in blood
(D) Inheritance is autosomal recessive
20. Synthesis of GMP and IMP requires the
following:
(A) NH3 NAD+, ATP
(B) Glutamine, NAD+, ATP
(C) NH3, GTP, NADP+
(D) Glutamine, GTP, NADP+
21. Which pathway is correct for catabolism
of purines to form uric acid?
(A) Guanylate→Adenylate→Xanthine→hypoxanthine→
Uric acid
(B) Guanylate→inosinate→Xanthine→hypoxanthine→
Uric acid
(C) Adenylate→Inosinate→Xanthine hypoxanthine→
Uric acid
(D) Adenylate→Inosinate→hypoxanthine
Xanthine→Uric acid
22. Polysemes do not contain
(A) Protein (B) DNA
(C) mRNA (D) rRNA
23. The formation of a peptide bond during
the elongation step of protein synthesis
results in the splitting of how many high
energy bonds?
(A) 1 (B) 2
(C) 3 (D) 4
24. Translocase is an enzyme required in the
process of
(A) DNA replication
(B) RNA synthesis
(C) Initiation of protein synthesis
(D) Elongation of peptides
25. Nonsense codons bring about
(A) Amino acid activation
(B) Initiation of protein synthesis
(C) Termination of protein synthesis
(D) Elongation of polypeptide chains
26. Which of the following genes of the E.coli
“Lac operon” codes for a constitutive
protein?
(A) The ‘a’ gene (B) The ‘i’ gene
(C) The ‘c’ gene (D) The ‘z’ gene
27. In the process of transcription, the flow
of genetic information is from
(A) DNA to DNA (B) DNA to protein
(C) RNA to protein (D) DNA to RNA
28. The anticodon region is an important part
of the structure of
(A) rRNA (B) tRNA
(C) mRNA (D) hrRNA
29. The region of the Lac operon which must
be free from structural gene transcription
to occur is
(A) The operator locus
(B) The promoter site
(C) The ‘a’ gene
(D) The ‘i’ gene
30. Another name for reverse transcriptase is
(A) DNA dependent DNA polymerase
(B) DNA dependent RNA polymerase
(C) RNA dependent DNA polymerase
(D) RNA dependent RNA polymerase
