ubiquinone dehydrogenase
Last reviewed 01/2018
Ubiquinone dehydrogenase is a large enzyme complex within the inner mitochondrial membrane. It is an intermediate in the electron transfer chain.
It consists of:
- cytochrome b:
- has haem prosthetic group
- accepts electrons from ubiquinone to produce an Fe 2+ redox state
- transfers electron to ubiquinol to recycle Fe 3+ state
- ubiquinol: transfers electron to ferrous carrier by oxidation
- ferrous carrier: transfers electron to cytochrome c1 by oxidation
- cytochrome c1:
- contains haem prosthetic group
- reduced by transfer of electrons from ferrous carrier
- reoxidized by transfer of electrons to cytochrome c
The passage of 1 electron through the ubiquinone dehydrogenase complex acts to pump 1 proton into the mitochondrial intermembranous space. Ultimately, this produces 1 molecule of ATP through oxidative phosphorylation.