The enzyme malate decarboxylase, which catalyzes the reaction shown in Eq. 20.48, contains a molecule of tightly bound NAD⁺, which undergoes no net change as a result of the reaction. Without the NAD⁺, the enzyme is completely inactive as a catalyst. Explain the role of the NAD⁺ in facilitating the decarboxylation of malic acid.

Transcribed Image Text:

O OH HO-C-CH-CH₂-C-OH malic acid malate decarboxylase (enzyme) O OH HỌ—C—CH—CH3 + CO, lactic acid (20.48)