The 10 enzymes of glycolysis are: hexokinase, phosphoglucose isomerase, phosphofructokinase, aldolase, triose phosphate isomerase, glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase, phosphoglycerate mutase, enolase, and pyruvate kinase.
Glycolysis is a fundamental metabolic pathway that converts glucose into pyruvate, producing a small amount of ATP and NADH. Each step of this pathway is catalyzed by a specific enzyme. Here's a breakdown of each enzyme:
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Hexokinase: Catalyzes the phosphorylation of glucose to glucose-6-phosphate. This is an irreversible step, trapping glucose inside the cell and committing it to glycolysis.
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Phosphoglucose Isomerase: Catalyzes the isomerization of glucose-6-phosphate to fructose-6-phosphate. This conversion is necessary for the next phosphorylation step.
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Phosphofructokinase (PFK-1): Catalyzes the phosphorylation of fructose-6-phosphate to fructose-1,6-bisphosphate. This is a major regulatory point in glycolysis and is also an irreversible step.
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Aldolase: Cleaves fructose-1,6-bisphosphate into two three-carbon molecules: dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (G3P).
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Triose Phosphate Isomerase: Catalyzes the interconversion of DHAP and G3P. Only G3P can proceed further in glycolysis, so this enzyme ensures that DHAP is converted to G3P.
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Glyceraldehyde-3-phosphate Dehydrogenase: Catalyzes the oxidation and phosphorylation of G3P to 1,3-bisphosphoglycerate. This step also produces NADH.
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Phosphoglycerate Kinase: Catalyzes the transfer of a phosphate group from 1,3-bisphosphoglycerate to ADP, forming ATP and 3-phosphoglycerate. This is the first ATP-producing step in glycolysis.
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Phosphoglycerate Mutase: Catalyzes the isomerization of 3-phosphoglycerate to 2-phosphoglycerate. This prepares the molecule for the next dehydration step.
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Enolase: Catalyzes the dehydration of 2-phosphoglycerate to phosphoenolpyruvate (PEP). This creates a high-energy phosphate bond.
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Pyruvate Kinase: Catalyzes the transfer of a phosphate group from PEP to ADP, forming ATP and pyruvate. This is the second ATP-producing step in glycolysis and is an irreversible step.
These ten enzymes work in concert to convert glucose into pyruvate, generating ATP and NADH along the way. The pyruvate produced can then enter the citric acid cycle or undergo fermentation, depending on the availability of oxygen and the metabolic needs of the cell.
