Function
NADH Dehydrogenase is the first enzyme (Complex I) of the mitochondrial electron transport chain. There are three energy-transducing enzymes in the electron transport chain - NADH dehydrogenase (Complex I), Coenzyme Q – cytochrome c reductase (Complex III), and cytochrome c oxidase (Complex IV). NADH dehydrogenase is the largest and most complicated enzyme of the electron transport chain.
The reaction of NADH dehydrogenase is:
- NADH + H+ + CoQ + 4H+in → NAD+ + CoQH2 + 4H+out
In this process, the complex translocates four protons across the inner membrane per molecule of oxidized NADH, helping to build the electrochemical potential used to produce ATP.
The reaction can be reversed - referred to as aerobic succinate-supported NAD+ reduction - in the presence of a high membrane potential, but the exact catalytic mechanism remains unknown.
Complex I may have a role in triggering apoptosis. In fact, there has been shown to be a correlation between mitochondrial activities and programmed cell death (PCD) during somatic embryo development.
Read more about this topic: NADH Dehydrogenase
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