What are the roles of the different enzymes involved in glycolysis?

Enzymes in glycolysis facilitate the breakdown of glucose into pyruvate, generating ATP and NADH in the process.

Glycolysis is a metabolic pathway that breaks down glucose, a six-carbon sugar, into two molecules of pyruvate, a three-carbon compound. This process is facilitated by a series of enzymes, each playing a unique role in the different steps of glycolysis.

The first enzyme, hexokinase, initiates glycolysis by phosphorylating glucose, converting it into glucose-6-phosphate. This step is crucial as it traps the glucose inside the cell and prepares it for further breakdown. The second enzyme, phosphoglucose isomerase, then converts glucose-6-phosphate into fructose-6-phosphate.

The third enzyme, phosphofructokinase, adds another phosphate group to the fructose-6-phosphate, forming fructose-1,6-bisphosphate. This is a key regulatory step in glycolysis, as phosphofructokinase is allosterically inhibited by high levels of ATP, preventing excessive glucose breakdown when energy levels are high.

Next, aldolase splits fructose-1,6-bisphosphate into two three-carbon compounds, glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. Triose phosphate isomerase then converts dihydroxyacetone phosphate into another molecule of glyceraldehyde-3-phosphate.

Glyceraldehyde-3-phosphate dehydrogenase then oxidises and adds a phosphate group to the two molecules of glyceraldehyde-3-phosphate, forming 1,3-bisphosphoglycerate. This step also generates two molecules of NADH, a high-energy electron carrier.

The next enzyme, phosphoglycerate kinase, transfers a phosphate group from 1,3-bisphosphoglycerate to ADP, forming ATP and 3-phosphoglycerate. This is followed by phosphoglycerate mutase, which rearranges 3-phosphoglycerate to form 2-phosphoglycerate.

Enolase then removes a water molecule from 2-phosphoglycerate, forming phosphoenolpyruvate. Finally, pyruvate kinase transfers a phosphate group from phosphoenolpyruvate to ADP, forming another molecule of ATP and pyruvate.

In summary, the enzymes in