In this article we compare the kinetic behavior toward pyridine nucleotides (NAD(+), NADH) of NAD(+)-malic enzyme, pyruvate dehydrogenase, isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, and glycine decarboxylase extracted from pea (Pisum sativum) leaf and potato (Solanum tuberosum)