Hello biologists and in today's session we are going to be looking at the importance of coenzymes in cellular respiration. This is taken from the OCR specification for A-level biology for respiration. Now there are three particular coenzymes we need to be aware of here and their roles so we'll go through each one and what they do. So on this side as you can see here we've got NAD, don't really need to know what that stands for that is just there for you if you're interested but NAD as we know accepts hydrogen atoms as their electrons in order to become reduced NAD. Now NAD is used in glycolysis, it's also used in the link reaction and it's also used in the quebec cycle so in all three parts here of these three parts of respiration NAD is reduced. Now, the NAD will be used in the final process of aerobic respiration, which we haven't quite covered yet, oxidative phosphorylation. But NAD is used in both the aerobic and anaerobic pathways. The next coenzyme we're going to look at is coenzyme A and the role of coenzyme A is to carry acetate or ethanoic groups made from the pyruvate in the link reaction into the Krebs cycle. Once it's dropped off almost its acetate in the Krebs cycle, the coenzyme A will then go back to collect more acetate from the product and the link reaction. so that's coenzyme nad next one we're going to look at is fad so fad again don't need to know what that means fad you just need to know that again this accepts hydrogen atoms and their electrons in order to become reduced fad now this one in respiration is only used in the krebs cycle and therefore is only used in aerobic respiration So there we have our three coenzymes that we need to be aware of and their role within respiration. They are vital for respiration to take place. Without them, respiration, aerobic or anaerobic process would not be able to take place. They are absolutely vital for this role. Guys, as ever in your exams, please remember, do not use the words it, they, amount and size. Use good scientific biological terminology that will get you marks and good luck.