Abstract:Electron leakage rate and respiratory rate were studied with mung beau mitochondria. Succinate, NADH, a-ketoglutarate, malate and NADH were strongly effective in supporting mitochondrial respiratory rate and electron leakage rate. The ratio of electron leakage rate and respiratory rate (O2-./O2) were not markedly different when different substrates were utilized in mung beau mitochondria. Electron leakage rate was promoted and respiratory rate was inhibited by antimycin-A when succinate, a-ketoglutarate and