Which of the following statements about glycogen is true?
I. Glycogen is a polymer of glucose in $\alpha$ (1 $\rarr$ 6) linkages with $\alpha$ (1 $\rarr$ 4) linked branches every 8-14 residues.
II. UDP-glucose is produced from glycogen by the action of the enzyme phosphorylase.
III. In glycogen breakdown, glucose residues are sequentially removed from the nonreducing ends.
IV. The breakdown of glycogen in skeletal muscle ultimately supplies glucose-6-phosphate, which can enter glycolysis to generate ATP.

Question

Which of the following statements about glycogen is true?
I. Glycogen is a polymer of glucose in  $\alpha$ (1  $\rarr$ 6) linkages with  $\alpha$ (1  $\rarr$ 4) linked branches every 8-14 residues.
II. UDP-glucose is produced from glycogen by the action of the enzyme phosphorylase.
III. In glycogen breakdown, glucose residues are sequentially removed from the nonreducing ends.
IV. The breakdown of glycogen in skeletal muscle ultimately supplies glucose-6-phosphate, which can enter glycolysis to generate ATP.

Quizplus · Accepted Answer

Statement III is true because glycogen phosphorylase removes glucose residues from the nonreducing ends. Statement IV is true because glycogen breakdown in muscle provides glucose-6-phosphate for glycolysis. Statement I is incorrect because glycogen has α(1→4) linkages with α(1→6) branches. Statement II is incorrect because UDP-glucose is a precursor in glycogen synthesis, not a product of glycogen breakdown.

Which of the Following Statements About Glycogen Is True? I α\alphaα

Which of the Following Statements About Glycogen Is True?
I $\alpha$