MUSCLE PHYSIOLOGY

Detailed explanation-1: -One glucose molecule yields four ATP molecules in total during glycolysis. Since 2 ATP molecules are used up in the first phase of glycolysis, there is a net gain of 2 ATP molecules.

Detailed explanation-2: -During glycolysis, glucose ultimately breaks down into pyruvate and energy; a total of 2 ATP is derived in the process (Glucose + 2 NAD+ + 2 ADP + 2 Pi–> 2 Pyruvate + 2 NADH + 2 H+ + 2 ATP + 2 H2O).

Detailed explanation-3: -Although four ATP molecules are produced in the second half, the net gain of glycolysis is only two ATP because two ATP molecules are used in the first half of glycolysis.

Detailed explanation-4: -2 molecules of ATP are utilised in the glycolysis. One molecule of ATP is utilised when glucose is converted to glucose-6-phosphate and the other is utilised when fructose-6-phosphate is converted to fructose-1, 6-bisphosphate. So, the net gain of ATP molecules during glycolysis is 2.

Detailed explanation-5: -Glycolysis produces only two net molecules of ATP per 1 molecule of glucose. However, in cells lacking mitochondria and/or adequate oxygen supply, glycolysis is the sole process by which such cells can produce ATP from glucose.