chambers32 - GLYCOLYSIS GLYCOLYSIS Reading: Harpers...

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: GLYCOLYSIS GLYCOLYSIS Reading: Harpers Biochemistry pp. 190-198 Lehninger Principles of Biochemistry 3rd Ed. pp. 527-566 Glycolysis- from the Greek- glykys- sweet lysis- splitting OBJECTIVES OBJECTIVES To understand how the glycolytic pathway is used to convert glucose to pyruvate (and lactate) with conservation of chemical potential energy in the form of ATP and NADH. To learn the intermediates, enzymes, and cofactors of the glycolytic pathway. Major pathways of glucose utilization in Major pathways of glucose utilization in cells of higher plants and animals cells of higher plants and animals Although not the only possible fates for glucose, these three pathways are the most significant in terms of the amount of glucose that flows through them in most cells. Glucose is the major fuel of most organisms. It is relatively rich in potential energy- complete oxidation to CO 2 and H 2 O proceeds with a free- energy change of -2,840 kJ/mol. By storing glucose as high molecular weight polymers (starch/glycogen) a cell can stockpile large quantities of hexose units. When energy demands increase, glucose can be released quickly from storage and used to produce ATP either aerobically or anaerobically. Glycolysis occurs in the cytosol of cells, is common to most organisms, and in humans occurs in virtually all tissues. Most tissues have at least a minimal requirement for glucose. In the brain, the requirement for glucose is substantial, in erythrocytes, it is nearly total. In glycolysis, a molecule of glucose is degraded in a series of steps catalyzed by ten cytosolic enzymes, to yield two molecules of the 3 carbon compound, pyruvate. During those sequential reactions, some of the free energy released is conserved in the form of ATP and NADH Biomedical Importance Biomedical Importance Of crucial biomedical significance is the ability of glycolysis to provide ATP in the absence of oxygen. This allows skeletal muscle to perform at high levels when aerobic oxidation becomes insufficient, and allows cells to survive anoxic episodes. Diseases associated with impaired glycolysis: Hemolytic anemia:- of the defects in glycolysis that cause hemolytic anemia, pyruvate kinase deficiency (genetic mutations) is the most common.- mature erythrocytes contain no mitochondria, totally dependent upon glycolysis for ATP.- ATP is required for Na/K-ATPase-ion transport system which maintain the proper shape of the erythrocyte membrane. Lactic Acidosis:- can be due to several causes of improper utilization of lactate. Glycolysis is only the first step in the Glycolysis is only the first step in the degradation of glucose degradation of glucose Three possible catabolic fates of the pyruvate formed in glycolysis. Pyruvate also serves as a precursor in many anabolic reactions, not shown here. Where glycolysis fits in Where glycolysis fits in the big picture of the big picture of catabolism catabolism Overview of Overview of glycolysis glycolysis Energy Transformations during Glycolysis...
View Full Document

Page1 / 29

chambers32 - GLYCOLYSIS GLYCOLYSIS Reading: Harpers...

This preview shows document pages 1 - 12. Sign up to view the full document.

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