MUSCLE PHYSIOLOGY

Detailed explanation-1: -The first step in glycolysis is catalyzed by hexokinase, an enzyme with broad specificity that catalyzes the phosphorylation of six-carbon sugars. Hexokinase phosphorylates glucose using ATP as the source of the phosphate, producing glucose-6-phosphate, a more reactive form of glucose.

Detailed explanation-2: -Step 1: Glucose is phosphorylated by the enzyme hexokinase to form glucose 6-phosphate. Glucose gains energy by being phosphorylated at the expense of one ATP. Step 2: Glucose 6-phosphate is converted into its isomer, fructose 6-phosphate, by an isomerase enzyme.

Detailed explanation-3: -Glucose is first converted to fructose-1, 6-bisphosphate in a series of steps that use up two ATP. Then, unstable fructose-1, 6-bisphosphate splits in two, forming two three-carbon molecules called DHAP and glyceraldehyde-3-phosphae.

Detailed explanation-4: -The major reason for the immediate phosphorylation of glucose is to prevent diffusion out of the cell. The phosphorylation adds a charged phosphate group so the glucose 6-phosphate cannot easily cross the cell membrane.

Detailed explanation-5: -The enzyme Hexokinase is known to catalyze the conversion of glucose to glucose-6-phosphate. It is an irreversible reaction and requires ATP. It is a part of glycolysis.