Question

1. How many oxidation steps take place in glycolysis per glucose molecule? How many phosphorylation steps per glucose molecule?

2. What is the net number of ATP molecules produced per glucose molecule during glycolysis? These ATP molecules are synthesized using which of the phosphorylation mechanisms: substrate level phosphorylation, or oxidative phosphorylation?

Answer 1

1. How many oxidation steps take place in glycolysis per glucose molecule? How many phosphorylation steps per glucose molecule?

The answer is : The removal of hydrogen or elections or addition of oxygen to the substrate is called oxidation. Only one oxidation step is present in Glycolysis, i.e. conversion of glycelrinaldehyde-3-phosphate to 1-3-biphosphoglycerate, during this converstion the stubstate i.e glycelrinaldehyde-3-phosphate losses two hydrogen molecules and conversts in to biphosphoglycerate. As the substrate losses hydrogen molecules it is marked as the oxidation step. During this step NADH moelcule will be generated.

Addition of phosphate is called as phosphorelation. During the glycolysis, the first and third steps are the phosphorelation steps i.e. conversion of glucose to glucose 6 phosphate and fructose 6 phosphate to fructiose 1,6 bi phosphate.

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2. What is the net number of ATP molecules produced per glucose molecule during glycolysis? These ATP molecules are synthesized using which of the phosphorylation mechanisms: substrate level phosphorylation, or oxidative phosphorylation?

The answer is: Total four molecuels of ATP generats during glycolysis through substrate level phosphoreltion as two ATP consumption occurs during phosphorelation of glucose molecules, the net atp is 4-2 = 2.