試題詳解

17. We have two enzymes maltose phosphorylase and sucrose phosphorylase catalyzing the following reactions:
With the presence of unlabeled G-1-P and sucrose phosphorylase in an isotope-labeled ³²P； solution, we found the "P" on G-1-P can also be isotope-labeled after some time. However, maltose phosphorylase cannot do the same. Which of following is true:
(A) Sucrose phosphorylase catalyzes a reaction following double-displacement mechanism
(B) Sucrose phosphorylase catalyzes a reaction requiring the formation of tertiary complexes
(C) Maltose phosphorylase catalyzes a reaction following what is called "Ping-Pong mechanism"
(D) Maltose phosphorylase catalyzes a reaction where enzyme is covalently modified during the catalysis though the modification occurs only transiently
(E) NAD+-dependent dehydrogenases use a random single-displacement catalytic mechanism