CSIR Biochemistry MCQ question part - 2

11. Denaturation of proteins leads to loss of biological activity by
(a) formation of amino acid
(b) loss of primary structure
(c) loss of both primary and secondary structure
(d) loss of secondary and tertiary structure

12. The pKa of acetic acid is 4.76. What is the pH of 0.1 M solution of acetic acid?
(a) 5.76 (b) 2.88
(c) 2.43 (d) 1.88

13. 40 g of ice at 0 °C and 80 g water at 40 oC are mixed thoroughly, the temperature of
the mixture will be
(a) 0° C (b) 10 °C
(c) 20 °C (d) 30 °C

14. Galactose and Mannose are two isomeric monosaccharides, which are
(a) Enantiomers (b) Epimers
(c) Anomers (d) Diastereoisorners

15. Proteins absorbs maximally UV radiation at 280 nm due to the presence of
(a) Tryptophan (b) Tyrosine
(c) Phenyl alanine (d) All of the above

16. Which one of the following solutions will have the least Osmotic Pressure?
(a) 0.5 M glucose (b) 0.5 M NaCl
(c) 0.5 M Na2SO4 (d) 0.499 M Starch

17. The free energy change (DG)at the midpoint of helix-coil transition in DNA melting
curve is equal to
(a) zero (b) 1.0
(c) –1.0 (d) indeterminate

18. DNA is usually dissolved in TRIS-EDTA buffer, EDTA is added to ensure that
(a) DNA is not degraded by nucleases
(b) Divalent metal ions are chelated
(c) Both of the above
(d) pH is kept alkaline

19. Two proteins have same molecular weight and same isoelectric point. The best way
to resolve them will be by
(a) Ion Exchange Chromatography
(b) Gel Filtration Chromatography
(c) Reverse Phase Chromatography
(d) Chromatofocussing

20. Mark the incorrect statement: Ribozyme and Abzyme are
(a) both enzymes
(b) both proteins
(c) RNA and protein respectively
(d) able to hydrolyse phosphodiester and peptide bonds respectively

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