MUSCLE PHYSIOLOGY

Detailed explanation-1: -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-2: -In the first step, glucose ⇢ glucose-6-phosphate, ATP is used and gets converted into ADP. Similarly, in the third step, fructose-6-phosphate ⇢ fructose-1, 6-biphosphate, ATP is used. Thus, two ATPs are used in the first three steps of glycolysis. Hence, to split the glucose 2 molecules of ATPs are used.

Detailed explanation-3: -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. In addition, glycolysis results in the production of 2 NADH molecules.

Detailed explanation-4: -These two steps take place two times in glycolysis. Hence, four molecules of ATP are synthesized. The steps such as conversion of glucose to glucose-6 phosphate and fructose-6 phosphate to fructose-1, 6 bisphosphate consumed two molecules of ATP. Thus net gain of ATP molecules in glycolysis is 2.