BIOC 3110 Lecture Notes - Lecture 26: Transketolase, Cytochrome P450, Epimerase And Racemase
28 Oct 2016
School
Department
Course
Professor
Document Summary
Function of pentose phosphate pathway: to take glycogen and make nadph (biosynthetic reducing power) and pentose sugars for dna and rna synthesis, and. We need nadph for anabolic pathways (synthesis: fatty acid, cholesterol, neurotransmitter, and nucleotide biosynthesis, also in detoxification (reduction of oxidized glutathione and cytochrome p450 monooxygenases, also in photosynthesis. The pentose phosphate pathway utilizes glucose-6-phosphate to make ribose-5-phosphate and nadph; it also interconverts 5c sugar to a 3c and 6c sugar (we get these from breakdown of nucleic acids and from diet) Oxidation occurs and moves electrons to nadp. Enzyme: g6p dehydrogenase, used in first step that forms nadph, regulated/committed step. Ribulose-5-p is interconverted to ribose-5-p by phosphopentose isomerase (5c sugar pool: the ribose-5-p can be used for nucleotides, rna, and dna. If cells only need nadph at the time, it just has to regenerate the 5c sugars to get more glucose-6-p. Or ribulose-5-p xylulose-5-phosphate by phosphopentose epimerase as a part of the pool, to go into nonoxidative.
