AP BIOLOGY

Detailed explanation-1: -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-2: -Glucose-6 phosphate is the first intermediate of glucose metabolism and plays a central role in the energy metabolism of the liver. It acts as a hub to metabolically connect glycolysis, the pentose phosphate pathway, glycogen synthesis, de novo lipogenesis, and the hexosamine pathway.

Detailed explanation-3: -Glycolysis produces 4 ATP molecules. However, 2 ATP molecules are required to initiate glycolysis.

Detailed explanation-4: -Reaction 1: Phosphorylation of glucose to glucose-6 phosphate. This reaction requires energy and so it is coupled to the hydrolysis of ATP to ADP and Pi. Enzyme: hexokinase. It has a low Km for glucose; thus, once glucose enters the cell, it gets phosphorylated.