So in step four, we take the alpha key to glutrate. We essentially reacted with coenzyme A, the same coenzyme A that we released in this particular case. And we also have the NAD plus the carrier for the electron. So in this step, what we want to do is we want to essentially kick off this carbon dioxide shown in blue and replace that with a coenzyme a, which is what we have in this particular case. In the process, we also abstract our electrons a hydride IoT and we place it onto the NADH or the NAD to form the NADH. So the NAD is reduced and the alpha key to gluten rate is oxidized.