NADH dehydrogenase

 The NADH complex is the largest of the respiratory enzyme complexes. It contains more than forty polypeptide chains. It's main role is to accept electrons from NADH and to pass them through over seven iron-sulfur centres and a flavin to ubiquinone. The electron transfer then continues when ubiquinone then transfers them to smaller second respiratory enzyme complex known as the cytochrome b-c1 complex.