IMED1003 Study Guide - Final Guide: Cytosol, Catabolism, Pyruvate Dehydrogenase
IMED1003 Final Revision Notes 2
LECTURE 9: PPP/AM - see full notes for more details
Oxidative and Non-Oxidative sections of PPP:!
= If cell needs equal amounts of ribose-5P & NADPH, oxidative PPP proceeds"
= If the cell needs lots of NADPH but not ribose-5P (e.g. RBC), then non-oxidative PPP
converts excess ribose-5P to glucose-6P. !
Anaerobic Glycolysis:!
-Purpose: re-oxidise NADH to form NAD+ = can continue ATP production from
glycolysis!
-Purpose NOT TO PRODUCE LACTATE!
AM Pathway:!
-2ATP generated per molecule of glucose !
-(as opposed to 38ATP with complete oxidation in presence of O2)!
-Lots of glucose can break down in aerobic metabolism in very short time!
Alcohol dehydrogenase helps with reduction:!
-NAD+ to NADH!
Lactate that’s pumped out into blood:
-CORI CYCLE!
-Helps rescue lactate, thus pH of blood will be maintained! !
-Eg. In hypoxia!
Hypoxia:!
-Low O2 concentration!
-Causes inhibition of ETC!
-thus low ATP in mitochondria!
-Anaerobic glycolysis!
-Glycogen depleted = lactate increase!
PPP:!
-Continues from intermediates of glycolysis !
-IMPORTANT enzyme to remember = glucose-6P dehydrogenase (G6PDH)
-Accumulated NADPH to make ribose 5-phosphate and convert it to G6PDH to continue
providing NADPH!
Red Blood Cells:
-RBC needs NADPH!
-PPP produces NADPH !
-NADPH = biologically strong reducing agent e.g. fatty acid biosynthesis !
Document Summary
Lecture 9: ppp/am - see full notes for more details. = if cell needs equal amounts of ribose-5p & nadph, oxidative ppp proceeds. = if the cell needs lots of nadph but not ribose-5p (e. g. rbc), then non-oxidative ppp converts excess ribose-5p to glucose-6p. Purpose: re-oxidise nadh to form nad+ = can continue atp production from glycolysis. (as opposed to 38atp with complete oxidation in presence of o2) Lots of glucose can break down in aerobic metabolism in very short time. Helps rescue lactate, thus ph of blood will be maintained! Important enzyme to remember = glucose-6p dehydrogenase (g6pdh) Accumulated nadph to make ribose 5-phosphate and convert it to g6pdh to continue providing nadph. Nadph = biologically strong reducing agent e. g. fatty acid biosynthesis. Reduced glutathione (gsh), particularly important in rbc. Lecture 8: gluconeogenesis & glycogen metabolism - see full notes for more details. If no glucose, will synthesise glucose via gluconeogenesis. Pyruvate enters mitochondria via proton gradient (transporter)
