Oxidation and Phosphorylation by Mitochondria from Green Stems

Open Access
Publisher Website
Google Scholar
Abstract
Particles isolated from green stems of tomato possessed the essential properties of mitochondria. Malate, succinate, fumarate, citrate, and a-ketoglutarate were oxidized, and the co-factors DPN, TPP, and CoA increased the rates of oxidation. Pyruvate served as a very poor substrate unless a catalytic amount of a Krebs cycle acid was added to the reaction mixture. Succinoxidase activity was among the highest known for plant mitochondria. Oxidation was coupled with phosphorylation, and P:O ratios between 2.3 and 3.2 were obtained with ketoglutarate. Phosphorylation depended on the addition of hexokinase to the reaction mixture. The preparation was relatively insensitive to DNP.