CHEM 153A Quiz: Week 9 SQ Part I Answers
9 Jan 2019
School
Department
Course
Professor
Document Summary
Part i: (a) what is the reaction catalyzed by the pyruvate dehydrogenase complex (no structures are necessary)? (b) what is the role of each enzyme. E1 (pyruvate decarboxylase): fully oxidizes the carboxylic group of pyruvate to co2 (decarboxylation), and transfers the other two carbons to e2. E2 (dihydrolipoyl transacetylase): transfers two remaining carbons of pyruvate to coenzyme a, forming acetyl-coa. E3 (dihydrolipoyl dehydrogenase): regenerates oxidized dihydrolipoamide, and reduces nad+ to nadh (c) how is this complex regulated? (d) why is this complex regulated? fermentation or gluconeogenesis. It produces a product that has many different sources and enzyme commits pyruvate to tca cycle vs: explain how multienzyme complexes can enhance reaction rates. By channeling substrates between enzymes it eliminates diffusion limitations of reaction rates, making them faster: explain how multienzyme complexes can channel reaction intermediates. Since the enzymes are physically associated they can pass intermediates between the enzymes.
