Question

Glycolysis or the stepwise degradation of glucose is a catabolic process, but the first step in this metabolic pathway requires ATP to phosphorylate glucose. What is the significance of phosphorylating glucose? How much ATP is generated for one molecule of glucose?

Answer 1

The transporters plays a role in glucose diffusion from out to in and in to out. As the needs energy, it needs to block the diffusion, so, as after phosphorelation, Glucose-6-Phosphate has a negative phosphate which cannot diffuse to trasporters. Hence, it is available to cell for glycolysis.

From one molecules of glucose during glycolysis, from substrate level of phosphorealtion 4 ATP molecules will be formed. but, as two will be utlized during phosphorelation steps, the net atp from glycolysis is 4-2 = 2