Question

Calculate how many ATP molecules are directly synthesised in this pathway from one glucose molecule?

Answer 1

Part 1: Introduction of glycolysis
Glycolysis is the first step of cellular respiration. It involves the partial oxidation of glucose molecule into two molecules of pyruvic acid.

Part 2: ATP consuming steps
In the preparatory phase, 2 molecules are consumed at 2 steps. Step 1: Conversion of Glucose to Glucose - 6 - phosphate
Step 3: Fructose-6-phosphate to Fructose-1,6-bisphosphate

Part 3: ATP synthesis steps
In the payoff phase, ATP is produced at 2 steps.
Step 7: Conversion of 1, 3 - bisphosphoglycerate to 3- phosphoglycerate
Step 10: Conversion of phosphoenolpyruvic acid to pyruvic acid.

Part 5: Net gain of ATP in glycolysis $C_6{H}_{12}{O}_6+2NA{D}^{+}+2P{O}_4^{2-}+2ADP\to \text{Pyruvate}+2NADH+2ATP+2H_{2}O+2H^{+}$

2 ATP molecules are directly synthesised from one molecule of glucose in glycolysis.