So let's begin with protein complex number one. Now, protein complex number one consists of many proteins. And together, protein complex number one is known as Nadhq oxidoreductase or NADH dehydrogenase. So it's called oxidoreductase because we have oxidation reduction reactions taking place. So what exactly is the purpose of protein complex Number One? Well, NADH Dehydrogenase basically accepts the electrons from NADH molecules produced in glycolysis, pyruvate carboxylation and the citric acid cycle.