Mitochondria are membrane-bound organelles found in the cytosol of eukaryotic cells and are responsible for cellular respiration. The electron transport chain of mitochondria (responsible for ATP production) contains three major membrane-bound respiratory enzymes: NADH dehydrogenase, cytochrome b-c1, and cytochrome oxidase. Cytochrome oxidase is a single terminal membrane-bound enzyme of the respiratory chain that accepts electrons from cytochrome c and passes them to oxygen.
4e – + 8H + in+ O2 —> 4H + out + 2H20
This presentation reports on the characterization of cytochrome oxidase in dark red kidney bean (Phaseolus vulgaris). The goal of my research was to develop a new lab for the Cell and Molecular Biology course (BIO 205) utilizing mitochondria, mitochondrial DNA (mtDNA), and the mitochondrial enzyme cytochrome oxidase. I developed the following protocols: differential centrifugations and sucrose gradients to isolate mitochondria, succinate dehydrogenase assay to confirm mitochondria were isolated, isolations of mtDNA, and Southern blot analysis to determine that the cytochrome oxidase gene resides on the mitochondrial chromosome. The results show that the mitochondria and mtDNA were successfully isolated and that the gene coding for wheat cytochrome oxidase has homology to the mtDNA of red kidney bean. This lab will be initiated in the fall semester of 1999.
Nicolas Rippel, ’99 Toluca, IL
Major: Biochemistry & Molecular Biology
Sponsors: Craig Tepper, Jeffrey Cardon