A 27-year-old man has been preparing for a marathon. As part of his normal prerace routine, he consumes a large meal consisting of pasta and mashed potatoes the night before the race. Which of the following enzymes is most likely to be stimulated in his hepatocytes, resulting in increased glycogen stores in this man?

Question

Quizplus · Accepted Answer

Glucokinase is an enzyme in the liver that facilitates the phosphorylation of glucose to glucose-6-phosphate, a key step in glycogen synthesis. It is stimulated by high glucose levels, such as after a carbohydrate-rich meal, leading to increased glycogen storage. High carbohydrate loading, as is typical for distance runners, results in an increased level of insulin release from the pancreas. Insulin effects on the liver include changes in the activities of several enzymes, such as that of glucokinase. Glucokinase is the hepatic form of the glucose-phosphorylating enzymes.

A 27-Year-Old Man Has Been Preparing for a Marathon