Biomolecules — DU B. Sc. (Hons) Biochemistry Previous Year Question Papers

5. (a). Give the reaction for the following (any four: (i) Effect of Alkali on RNA (il) Action of phospholipase A2 on lecithin (iii) Decarboxylation of Histidine (iv) Action of alkali on Glucose (V) Action of lactase on lactose (b) Draw a labelled titration curve of histidine and - discuss how it can act as a buffer at physiological pH. (c) Give the structural features of aggrecan. 6. Write short notes (any 3): 2. There are 6 questions. 4. Attempt 4 questions in all. 1. (a) State True/False with explanation : (i) Degree of unsaturation in lipids can be measured by saponification number. (ii) The beta anomer of D-Glucose has a more stable conformation than the alpha form. (ili) Proline and cysteine are called "helix breakers". (iv) Glycosaminoglycans have a slippery gel-like consistency. (v) Melting temperature of DNA is sequence independent. (b) Define the following : 2. (a) Identify and give the structure (any six) : (i) An Unusual base in RNA (ii) A non-reducing di saccharide (iv) Structural polysaccharide found in insects (v) Achiral amino acid (vi) A dicarboxylic amino acid (vii) A phospholipid without a glycerol backbone (b) Explain briefly: (ii) Chargaff's Law (9,6) 3. (a) What are ether lipids? Discuss with a suitable example. (b) Name the disease associated with the deficiency of vitamin B1, C, D, A, B2 and B12. (c) Describe the features of the DNA double helix. Differentiate between: (ii) Enantiomers and Diastereomers (iii) Aldonic acids and Uronic acids (iv) Waxes and triacylglycerols (vi) Omega-3 and Omega-6 fatty acids