LIFE SCIENCE

Detailed explanation-1: -Explanation: The conversion of glucose to two pyruvate molecules in glycolysis produces a net total of two direct ATP. When fructose-1, 6-bisphosphate enters glycolysis, it bypasses the two steps involved that normally cost one ATP each, therefore, there is no required input and the net total is four produced ATP.

Detailed explanation-2: -Fructose-1, 6-bisphosphate splits to form two three-carbon sugars: dihydroxyacetone phosphate ( DHAPstart text, D, H, A, P, end text) and glyceraldehyde-3-phosphate. They are isomers of each other, but only one-glyceraldehyde-3-phosphate-can directly continue through the next steps of glycolysis.

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.

Detailed explanation-4: -Fructose-1, 6-bis phosphate can not directly enter into glycolysis. It should convert into glucose which yields 2 ATP molecules. Then this glucose enters into glycolysis and citric acid cycle which yields 38 ATP molecules.

Detailed explanation-5: -First ATP is produced when glyceraldehyde-3-phosphate ⇢ 1, 3 diphosphoglycerate. Secondly ATP is produced when phosphoenolpyruvate ⇢ pyruvate. These reactions occur twice for both molecules of 3-phosphate. Thus, a total of 4 ATPs are produced during glycolysis.