BCHS-4361-09-G-6-P-D_38316

BCHS-4361-09-G-6-P-D_38316 - GLUCOSE-6-PHOSPHATE...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
GLUCOSE-6-PHOSPHATE DEHYDROGENASE DEFICIENCY Glucose-6-phosphate dehydrogenase (G6PDH) deficiency can be considered as a “bridge” in thinking about problems relating to red cell function and disorders in carbohydrate metabolism. This sex-linked recessive disorder results from a defective step in the pentose phosphate pathway (PPP) whose operation is essential to maintain the proper oxidative environment in the red cell. It is the most common enzymatic deficiency in red cells and its most severe form, it gives rise to a hemolytic anemia.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Pentose phosphate pathway A.k.a “pentose shunt” or “hexose monophosphate” shunt Major Functions: Synthesis of pentose sugars for DNA, RNA, ATP, NADH, FAD Generate NADPH from NADP + for biosynthetic reactions Minor Functions: Interconversion of 3,4,5,6, and 7 carbon sugars Generate glycolytic intermediates Rate is controlled by levels of NADP + Glucose-6-P dehydrogenase
Background image of page 2
Glucose-6- phosphate dehydrogenase 6-phospho- gluconolactonase Phosphogluconate dehydrogenase
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Figure 1. A scenario in which the cell requires NADPH but does not require ribose-5-P NADPH is used for biosynthetic reactions and glutathione metabolism Glucose-6-P-dehydrogenase Glucose Glucose 6-P ATP ADP 6-Phosphogluconate NADP NADPH Ribulose 5-P CO 2 NADPH NADP 6-P gluconate dehydrogenase Oxidative branch Xylulose 5-P Ribose 5-P (5 carbons) Sedoheptulose 7-P (7 carbons) Erythrose 4-P Transketolase Transaldolase Glyceraldehyde 3-P Fructose 6-P Fructose 6-P TDP TDP Transketolase Non-oxidative branch Glyceraldehyde 3-P Glyceraldehyde-3-P and fructose-6-P return to the glycolytic pathway
Background image of page 4
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 6
Author Unknown
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 8
RBC Metabolism Simplified Glucose Glucose Anaerobic Anaerobic glycolysis glycolysis Aerobic metabolism Aerobic metabolism Glucose-6-P Glucose-6-P G6PDH G6PDH Detoxification of metabolites Detoxification of metabolites of oxidative stress of oxidative stress Elimination of Elimination of methemoglobin methemoglobin (minor pathway) (minor pathway) F-6-P F-6-P
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
G6PDH REGULATION When the diet contains large amounts of carbohydrate, the amount of G6PDH rises, up to 10 fold in going from starvation to satiation. Well nourished individuals convert excess carbohydrate to fatty acid, a process that requires a lot of NADPH. A finer level of control is exerted by NADPH acting
Background image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 28

BCHS-4361-09-G-6-P-D_38316 - GLUCOSE-6-PHOSPHATE...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online