In alcoholic fermentation, each mole of pyruvate is converted to one mole of carbon dioxide and one mole of ethanol. In the process, about 50 kcal/mol (209 kJ/mol) of energy is produced. Under the most favorable conditions, more than one-half of this energy is stored as ATP.
a. What happens to the remaining energy produced in alcoholic fermentation?

Question

In alcoholic fermentation, each mole of pyruvate is converted to one mole of carbon dioxide and one mole of ethanol. In the process, about 50 kcal/mol (209 kJ/mol) of energy is produced. Under the most favorable conditions, more than one-half of this energy is stored as ATP.
a. What happens to the remaining energy produced in alcoholic fermentation?

a. What happens to the remaining energy produced in alcoholic fermentation?

Accepted Answer

Hello everyone. And welcome back. Our next problem says during alcoholic fermentation, each mole of pyruvate is transformed into one mole of carbon dioxide and one mole of ethanol resulting in the generation of energy true or false. All the energy generated during alcoholic fermentation is stored exclusively as at P. So let's think about this process and think through how the energy that's generated is stored. So this phrasing is just a little bit confusing because our description of reaction focuses on pyruvate being converted into carbon dioxide and ethanol. But the whole process of alcoholic fermentation also includes glycolysis. We start with glucose which goes through glycolysis to produce pyre. That will be two molecules of pyruvate because um glucose gets split. It's a six carbon molecule. Pyruvate is a three carbon molecule and the pyruvate will be converted into carbon dioxide and ethanol. So why is this important? Because the glycolysis part of the process is where the energy is generated and some of that is generated as a TP but some of it is generated by the production of N A DH, which is an electron carrier. And that brings electrons which usually in our cellular respiration process would be dropped off in the electron transport chain for oxidated phosphorylation. But when we're talking about fermentation, we don't have oxidated phosphor phosphorylation happening. So instead these electrons are dropped off with pyruvate. And the result of that is the production or regeneration of N AD plus which funnels back into glycolysis. And the importance of this fermentation step. Uh The end fermentation step is that we can regenerate the N AD plus because otherwise those electrons have no other place to go and glycolysis will halt because there's no way to regenerate N AD plus for this first process of glycolysis. And then of course, because we know that entropy is increasing, we're never going to have a reaction where we just as of this perfect conversion of chemical energy into chemical energy, we will lose some as heat. So we're just going to put plus heat here. So how do we generate store this energy? Well, some is direct production of A TP and that's two A TP molecules per molecule glucose. So we'll add a little two there to remind ourselves and recall that's a net production because we use up some A TP and then produce some A TP. We produce two molecules of N A DH. And then we also produce some heat, add some more twos in there. The two pyruvate lead to two ne plus. So all of the energy generated during alcoholic fermentation is not stored exclusively as a TP. So our answer here is going to be false on this one. See you in the next video.

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Key Concepts

Energy Yield in Fermentation

ATP Production

Heat Loss in Metabolic Processes