Metabolism and Integration — DU B.Sc. (Hons) Biological Sciences Previous Year Question Papers

I. A. Justify th`efoll,`owing statements. (any 5) i. ii. Ammonia is toxic to cells. Glycine is an inportant precursor for.de novo synthesis ofpurines. rii` Triglycerides are suitable energy reserves ofthev cell than c-arbQhydrates., iv. Conversion of Glyceraldehyde~3-phosphate to 3-phosphoglycerate is an energy coupling process. v. Vertebrates cannot convert fatty acid into glucose. vi. Living organisms are open systems. 8. Give an example each of a reaction requiring the following coenzyme: iv, PLP v. FAD+ 2. Differentiate between the fouowing pairs : i. Glucogenic & ketogenic amino acids ii, Carbamoy] phosphate synthetase I & 11 iii. Substrate level phosphorylation and oxidative phosphorylation iv. De novo and salvage pathway of purine biosynthesis v. Anabolism and catabolism Standard free energy change is directly related to equilforium constant. Explain. Explain in detall the reciprocal regulation of glycolysis and gluconeogenesis. 4. A. How is acetyl coA that is produced in the mitochondria transferred to cytosol for fatty acid biosynthesis? Calculate the number of ATP molecules produced when one molecule of Palmitate is completely oxidized. Briefly explain the lipoprotein cycle. 5. A. What is the significance of the Pentose phosphate pathway? Describe the fate of Glucose- 6-phosphate when the need for NADPH exceeds that of Ribose-5-phosphate. • Explain the metabolic shifts that occur during starvation and the well-fed stage. Describe Malate-Aspartate shuttle system. 6. A. Write down the steps to accomplish the following conversions - any 3 B. Explain in detail the urea cycle and its regulation C. Explain the regulation of Glycoger phosphorylase enzyme