Compared to metabolic activity during the daytime, when three meals are eaten, an overnight fast should cause all of the following EXCEPT
A) an increased rate of glycogenolysis.
B) increased activity of phosphoenolpyruvate carboxykinase.
C) increased rates of protein synthesis.
D) decreased activity of acetyl-CoA carboxylase.
E) increased activity of pyruvate carboxylase.

Question

Quizplus · Accepted Answer

During an overnight fast, the body's metabolic activity shifts towards the breakdown of stored energy to maintain blood glucose levels. This includes the activation of glycogenolysis, which breaks down stored glycogen into glucose, and increased activity of enzymes like pyruvate carboxylase and phosphoenolpyruvate carboxykinase that help form glucose from non-carbohydrate sources. Acetyl-CoA carboxylase, which catalyzes the formation of fatty acids, is inhibited during fasting to help preserve glucose for energy. However, protein synthesis is typically decreased during fasting as the body prioritizes energy conservation over building new tissues.

Compared to Metabolic Activity During the Daytime, When Three Meals