LOYOLA COLLEGE (AUTONOMOUS), CHENNAI –600 034

B.Sc., DEGREE EXAMINATION – CHEMISTRY

FIFTH SEMESTER – NOVEMBER 2003

CH – 5401/520/CHE 401 – BIO-CHEMISTRY

10-11-2003                                                                                                     Max:100 marks

1.00 – 4.00

PART – A

Answer ALL the questions.                                                                              (10×2=20 marks)

1. Define isoelectric point.
2. How is aninoacid tested using Ninhydrin? Indicate the reaction.
3. What are the two tertiary structures possible for a polypeptide? Give one example for each.
4. What is transamination reaction? Mention one example.
5. What is ATP? Give its structure.
6. What is ‘allosteric’ enzymes? How does it affect the rate of a reaction?
7. Suggest a chemical test for cholesterol.
8. What is the reaction of glucose with an amine?
9. Indicate the hydrogen bonding between A – T, G-C.
10. Mention any two differences between DNA and RNA?

 

PART – B

Answer any EIGHT questions.                                                                        (8×5=40 marks)

11. Suggest a synthetic route for ala-gly-ph ala.
12. Explain one method for C-terminal analysis of a polypeptide?
13. Explain all the steps involved in the ‘b-oxidation of fattyacid’.
14. How is the ring size of glucose determined?
15. Write briefly about competitive inhibition of enzymes.
16. How are enzymes classified? How is the enzyme action affected by pH?
17. Explain the mechanism of oxidative phosphorylation and explain the steps involved in this process.
18. Bring out the salient features of secondary structure of DNA.
19. Define genetic code. How is genetic information decoded for protein synthesis?
20. Write all the steps involved in the bio-synthesis of fattyacids.
21. Explain how blood is coagulated?

 

PART – C

Answer any FOUR questions.                                                                         (4×10=40 marks)

22. a) Define anabolism and catabolism. How are amino acids catabolyzed?
23. b) Discuss the advantage of preparing polypeptides by solid phase synthesis.
24. Explain how Michalis-Menton model helps in understanding the characteristics of enzyme catalysis. Derive the expression for the rate of enzyme catalysis.
25. Out line the steps in the bio-synthesis of cholesterol.
26. Describe the secondary structure of proteins.
27. Describe the steps involved in a) tricarboxylic acid cycle b) Glycolysis and energetics of glycolysis.
28. Explain the mechanism of transport of oxygen by blood.

 

 

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