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Krebs cycle step 6
From Proteopedia
Step 6 of the Krebs cycle: Succinate Dehydrogenase
Figure: Formation of Fumarate
In the sixth step, succinate is converted to fumarate; here, a dehydrogenation takes place because two protons are removed. FAD serves as coenzyme wich is bound covalently to the enzyme succinate dehydrogenase, so that usually the notation E-FAD is used. The liberated protons (in yellow) are taken up by FAD which is oxidised to FADH2. Unlike NADH, FADH2 does not need to be funneled into the respiratory chain, but is reduced directly in the enzyme back to FAD, and the reaciton can take place with another succinate molecule.
