AP BIOLOGY

Detailed explanation-1: -The enzyme phosphofructokinase transforms fructose-6-phosphate to fructose-1, 6-diphosphate. Decreased activity of this enzyme results in increased muscle glycogen stores of normal structure and increased concentration of glucose-6-phosphate and fructose-6-phosphate (Musumeci et al., 2012).

Detailed explanation-2: -Fructose 6-phosphate is converted to fructose 1, 6-diphosphate catalyzed by phosphofructose kinase, along with the consumption of an ATP molecule.

Detailed explanation-3: -The great majority of glucose is converted to fructose 6-phosphate upon entering a cell. Fructose is predominantly converted to fructose 1-phosphate by fructokinase following cellular import.

Detailed explanation-4: -Fructose-1, 6-diphosphatase is the key regulator of gluconeogenesis, during which it catalyzes the hydrolysis of fructose-1, 6-bisphosphate to fructose-6-phosphate and inorganic phosphate. This enzyme is expressed in several tissues with maximum activity in the liver and kidney.

Detailed explanation-5: -In hepatocytes, fructose is phosphorylated to fructose-1-phosphate (F1P) by the enzyme fructokinase.