Enzymes facilitate reactions in living systems. Figure Q3-29 presents an energy diagram for the reaction Xa`Y. The solid line in the energy diagram represents changes in energy as the reactant is converted to product under standard conditions. The dashed line shows changes observed when the same reaction takes place in the presence of a dedicated enzyme. Which equation below indicates how the presence of an enzyme affects the activation energy of the reaction (catalyzed versus uncatalyzed)?
(a) d-cversusb-c
(b) d-aversusb-a
(c) a + d versus a + b
(d) d-c versus b-a
Answer: B