MDP10508 ENDOCRINE AND NUTRITION
ANSWER ALL OF THE QUESTIONS BELOW. (70 marks)
1. Comment on the statement below:
‘Glycolysis and Gluconeogenesis are reciprocally regulated’
Reciprocally regulated means when one process takes place in a cell, the other process will essentially inactivated. This regulation ensures that either glycolysis or gluconeogenesis predominate as to prevent concurrent activity in two closely parallel pathways, where if both Glycolysis and Gluconeogenesis happen at the same exact moment, , the net result would be the hydrolysis of four nucleotide triphosphates (two ATP plus two GTP) per reaction cycle. However, this non reciprocal regulation is a futile cycle, which would simply waste ATP if allowed to run freely. In reciprocal regulation, the amounts and activities of the distinctive enzymes of each pathway are…show more content… Discuss the Luebering-Rapapport Pathway and its significance.
In biochemistry, the Luebering-Rapoport pathway (also called the Luebering-Rapoport shunt) is a metabolic pathway in mature erythrocytes involving the formation of 2,3-bisphosphoglycerate (2,3-BPG), which regulates oxygen release from hemoglobin and delivery to tissues. 2,3-BPG, the reaction product of the Luebering-Rapoport pathway was first described and isolated in 1925 by the Austrian biochemist Samuel Mitja Rapoport and his technical assistant Janet Luebering. Through the Luebering-Rapoport pathway bisphosphoglycerate mutase catalyzes the transfer of a phosphoryl group from C1 to C2 of 1,3-BPG, giving 2,3-BPG. 2,3-bisphosphoglycerate, the most concentrated organophosphate in the erythrocyte, forms 3-PG by the action of bisphosphoglycerate phosphatase. The concentration of 2,3-BPG varies inversely with the pH, since it is inhibitory to catalytic action of bisphosphoglyceromutase.
5. Discuss the metabolism of galactose and its entry into the glycolytic pathway. https://themedicalbiochemistrypage.org/galactose.php