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NUCLEIC ACIDS- Part 7
See all quizzes of NUCLEIC ACIDS- Part 7 here:
1 Ribothymidine is present in
(A) DNA (B) tRNA
(C) rRNA (D) hnRNA
2. Ten base pairs are present in one turn of
the helix in
(A) A-DNA (B) B-DNA
(C) C-DNA (D) Z-DNA
3. Transfer RNA transfers
(A) Information from DNA to ribosomes
(B) Information from mRNA to cytosol
(C) Amino acids from cytosol to ribosomes
(D) Proteins from ribosomes to cytosol
4. Ceramidase is deficient in
(A) Fabry’s disease (B) Farber’s disease
(C) Krabbe’s disease (D) Tay-Sachs disease
5. Ceramide is present in all of the following
except
(A) Plasmalogens (B) Cerebrosides
(C) Sulphatides (D) Sphingomyelin
6. Nucleotides required for the synthesis of
nucleic acids can be obtained from
(A) Dietary nucleic acids and nucleotides
(B) De novo synthesis
(C) Salvage of pre-existing bases and nucleosides
(D) De novo synthesis and salvage
7. De novo synthesis of purine nucleotide
occurs in
(A) Mitochondria (B) Cytosol
(C) Microsmes (D) Ribosomes
8. The nitrogen atoms for de novo synthesis
of purine nucleotides are provided by
(A) Aspartate and glutamate
(B) Aspartate and glycine
(C) Aspartate, glutamine and glycine
(D) Aspartate, glutamate and glycine
9 For de novo synthesis of purine nucleotides,
glycine provides
(A) One nitrogen atom
(B) One nitrogen and one carbon atom
(C) Two carbon atoms
(D) One nitrogen and two carbon atoms
10. For de novo synthesis of purine nucleotides,
aspartate provides
(A) Nitrogen 1 (B) Nitrogen 3
(C) Nitrogen 7 (D) Nitrogen 9
11. In the purine nucleus, carbon 6 is contributed
by
(A) Glycine (B) CO2
(C) Aspartate (D) Glutamine
12. 5-Phosphoribosyl-1-pyrophosphate is
required for the synthesis of
(A) Purine nucleotides (B) Pyrimidine nucleotides
(C) Both (A) and (B) (D) None of these
13. Inosine monophophate is an intermediate
during the de novo synthesis of
(A) AMP and GMP (B) CMP and UMP
(C) CMP and TMP (D) All of these
14. Xanthosine monophosphate is an
intermediate during de novo synthesis of
(A) TMP (B) CMP
(C) AMP (D) GMP
15. In the pathway of de novo synthesis of
purine nucleotides, all the following are
allosteric enzymes except
(A) PRPP glutamyl amido transferase
(B) Adenylosuccinate synthetase
(C) IMP dehydrogenase
(D) Adenylosuccinase
16. All of the following enzymes are unique
to purine nucleotide synthesis except
(A) PRPP synthetase
(B) PRPP glutamyl amido transferase
(C) Adenylosuccinate synthetase
(D) IMP dehydrogenase
17. PRPP synthetase is allosterically inhibited
by
(A) AMP (B) ADP
(C) GMP (D) All of these
18. An allosteric inhibitor of PRPP glutamyl
amido transferase is
(A) AMP (B) ADP
(C) GMP (D) All of these
19. An allosteric inhibitor of adenylosuccinate
synthetase is
(A) AMP (B) ADP
(C) GMP (D) GDP
20. An allosteric inhibitor of IMP dehydrogenase
is
(A) AMP (B) ADP
(C) GMP (D) GDP
21. GMP is an allosteric inhibitor of all the
following except
(A) PRPP synthetase
(B) PRPP glutamyl amido synthetase
(C) IMP dehydrogenase
(D) Adenylosuccinate synthetase
22. AMP is an allosteric inhibitor of
(A) PRPP synthetase
(B) Adenylosucciante synthetase
(C) Both (A) and (B)
(D) None of these
23. The first reaction unique to purine nucleotide
synthesis is catalysed by
(A) PRPP synthetase
(B) PRPP glutamyl amido transferase
(C) Phosphoribosyl glycinamide synthetase
(D) Formyl transferase
24. Free purine bases which can be salvaged
are
(A) Adenine and guanine
(B) Adenine and hypoxanthine
(C) Guanine and hypoxanthine
(D) Adenine, guanine and hypoxanthine
25. The enzyme required for salvage of free
purine bases is
(A) Adenine phosphoribosyl transferase
(B) Hypoxanthine guanine phosphoribosyl
transferase
(C) Both (A) and (B)
(D) None of these
26. Deoxycytidine kinase can salvage
(A) Adenosine
(B) Adenosine and deoxyadenosine
(C) Adenosine and guanosine
(D) Adenine and adenosine
27. Adenosine kinase can salvage
(A) Adenosine
(B) Adenosine and deoxyadenosine
(C) Adenosine and guanosine
(D) Adenine and adenosine
28. Salvage of purine bases is regulated by
(A) Adenosine phosphoribosyl transferase
(B) Hypoxanthine guanine phosphoribosyl
transferase
(C) Availability of PRPP
(D) None of these
29. The available PRPP is used preferentially
for
(A) De novo synthesis of purine nucleotides
(B) De novo synthesis of pyrimidine nucleotides
(C) Salvage of purine bases
(D) Salvage of pyrimidine bases
30. The end product of purine catabolism in
man is
(A) Inosine (B) Hypoxanthine
(C) Xanthine (D) Uric acid
