Course Code: BCHET-149
Assignment Code: BCHET-149/TMA/2023
Maximum Marks: 100

PART-A

1. a) Describe the method for fractionation of subcellular organelles.

b) What is the role of Golgi bodies in protein processing? Illustrate with the help of a diagram.

2. a) Name the storage polysaccharides present in animals and plants. Indicate the structural differences between these.

b) i) What are lipoproteins? Name the major groups of lipoproteins.
ii) What is the significance of phospholipids in the membrane structure and function.

3. a) Why are the amino acids called \(\alpha\)-amino acids? The amino acids tyrosine and tryptophan have nonpolar side chains; still these are placed in the uncharged polar group, why? Write the advantages of polar side chains in the amino acids.

b) Describe the stereochemistry of the peptide bond and explain how this is significant in restricting the number of conformations of a polypeptide chain.

4. a) How does the \(\mathrm{pH}\) affect the activity of enzymes in the biological systems? Illustrate your answer.

b) What is the significance of vitamins and minerals in the living system? Write one biochemical reaction in which the coenzyme of cyanocobalmin is associated and explain the mechanism of the reaction.

5. a) When is a reaction called spontaneous? Differentiate between \(\Delta G\) and \(\Delta G^{\circ}\) and describe their significance in predicting the direction of a biochemical reaction.

b) What is meant by the turnover of ATP? How is oxidative phosphorylation related to it? Write the steps involved in the phosphorylation process.

PART-B

6. a) Differentiate between anabolism and catabolism. Write the mechanism of the reaction of conversion of glyceraldehyde-3-phosphate to pyruvate.

b) Describe the process of biosynthesis of fatty acids catalysed by fatty acid synthase.

7. a) How is feedback regulation different from allosteric regulation? Name the most important regulatory enzyme and its allosteric effector in the glycolytic pathway. Also write the reaction catalysed by this enzyme.

b) Define photophosphorylation. Differentiate between substrate level and oxidative phosphorylation.

8. a) Describe the structure and role of ribosome in protein synthesis.

b) What are the advantages of using immobilized enzymes? How is the production of enzymes from microorganisms carried out?

9. a) Describe the role of DNA polymerase in DNA replication.

b) Describe the process of unwinding of the double helix during DNA replication.

10. a) Name two carbohydrates that are metabolised by glycolysis. Write the reactions and enzymes involved in their entry into the glycolytic pathway.

b) Describe the pathways involved in the removal of amino group from amino acids.