Final answer:
Phosphoglucomutase transfers a phosphoryl group from C-1 to C-6, forming fructose-6-phosphate, and then transfers a phosphate group from C-1 back to the active site, with the structure of the enzyme remaining unchanged.
Step-by-step explanation:
The active site of the enzyme phosphoglucomutase is a phosphoryl group, which is transferred from the C-1 position to the C-6 position of glucose-6-phosphate to form fructose-6-phosphate. Then, the enzyme transfers a phosphate group from C-1 back to the phosphoryl group at the active site. The structure of the enzyme remains unchanged throughout the reaction.