Question

Glucose is added to which end of a growing glycogen chain?

A. neither reducing nor nonreducing ends
B. both nonreducing and reducing ends
C. nonreducing ends
D. reducing end

Answer 1

Glucose is added to the reducing end of a growing glycogen chain by glycogen synthase through a-1→4 glycosidic linkages. Branching enzyme creates branching points by attaching glucose units to a-1→6 linkages.

Step-by-step explanation:

The correct answer is D. reducing end. Glucose is added to the reducing end of a growing glycogen chain. The reducing end is the end of the chain that has a free aldehyde or ketone group available for bonding. Glycogen synthase adds glucose to the glycogen primer through a-1→4 glycosidic linkages, forming a linear chain. Branching enzyme then creates branching points by removing glucose units from the linear chain and attaching them to a-1→6 linkages.