Carbohydrate Structure and Metabolism (1D) Practice Test

Investigators compare glucose utilization in resting skeletal muscle vs contracting skeletal muscle under identical blood glucose. Contracting muscle shows increased glycolytic flux and increased glucose uptake. The concept being tested is non-hormonal regulation of muscle glucose uptake during exercise. Which mechanism best explains increased glucose uptake in contracting muscle even without insulin?

Assume ATP demand rises during contraction.

A compound selectively inhibits phosphoglucomutase in skeletal muscle. Shortly after epinephrine exposure, muscle glycogen stores remain high despite activation of glycogen phosphorylase. The concept being tested is interconversion of glucose-1-phosphate and glucose-6-phosphate. Which immediate metabolic consequence is most consistent with phosphoglucomutase inhibition?

Reaction: glucose-1-phosphate  glucose-6-phosphate.