23. All are true for the isomerase reaction of glucose-6-phosphate to fructose-6-phosphate EXCEPT: (A) Mg2+ is required for activity (B) it is an aldose to ketose isomerization (C) "moving" the carbonyl from C-1 to C-2 creates a new primary alcohol group at C-1 (D) the reaction is irreversible with a large negative ΔG (E) the enzyme belongs to the isomerase class of enzymes