Biochemistry/Glycolysis
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[edit] Introduction
Glycolysis is the process by which glucose is converted to two molecules of pyruvate. It is the first step in carbohydrate metabolism, the end result of which is the conversion of glucose to carbon dioxide and water. In this process, a large amount of energy is converted into ATP.
During glycolysis, two molecules of NADH and a net two molecules of ATP are generated (two molecules of ATP are used to get the pathway started, but four molecules are then synthesized). Thus, there is a net production of two ATP molecules for each glucose molecule converted to two molecules of pyruvate.
[edit] The Ten Steps of Glycolysis
This is not correct, enzyme two is phosphohexose isomerase
[edit] Visual Overview of Reactions
Stage I: Energy Investment Image:1hexokinase.gif Image:2gpisomerase.gif Image:3pfk.gif Image:4aldolase.gif Image:5tpisomerase.gif Stage II: Energy Harvesting Image:6g3pDehydrogenase.gif Image:7pgkinase.gif Image:8pgmutase.gif Image:9enolase.gif Image:10pyruvatekinase.gif
[edit] Detailed Description of Reactions
(1) Glucose that enters the cell has only one fate: it is converted to glucose-6-phosphate by a typical kinase reaction. A pyrophosphate bond is cleaved (-7.5 kcal/mole) and a phosphate ester bond is formed (+3 kcal/mole), resulting in a net -4.0 kcal/mole. Therefore, this reaction is irreversible.
(2) Glucose-6-phosphate is then converted into Fructose-6-phosphate by a reversible isomerization.
Note: at body pH, phosphate groups are ionized, so PO3H2 would really be PO3(2-).
