When pyruvate is used to form acetyl CoA, the product has only two carbon atoms. What happened to the third carbon?

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Hi, everybody. Our next question says in the conversion of Pate to acetyl COA which of the following statements accurately describes or describe what happens to the third carbon atom. Select all that apply. And we have four statements. And our answer options are a one only B three, only C one and three or D one and four. Now, just to note in terms of test strategy, note that none of our answer choices offer the option, that statement two is correct. So if I'm gonna test, I can just cross out statement two and not even need to look at it. I know it can't be my answer. This is a practice problem. So we will look at it. So we're talking about pyruvate to acetyl coa. So let's recall that pyruvate. So we're pyruvate is a product of the glycolysis process and it is a three carbon molecule and then it undergoes pyruvate oxidation to become acetyl coa which is a two carbon molecule. So we lose a carbon along the way. What happens to it? Well, same thing that happens to all carbons and glucose as they, that glucose is being broken down, it gets expelled as carbon dioxide. So let's look at our other statements here. Seman one says the third carbon atom is expelled as carbon dioxide or CO2. And this is correct as we saw, that's where it goes. We go down to two carbons in that product there. So semen one is correct. So we know we can go and eliminate choice B three only statement two, we already know is incorrect on test. I wouldn't look at it. But again, in the interest of thus says the third carbon atom is converted into acetyl coa but acetyl coa has only two carbon atoms. So that's not the case. Then statement three says the third carbon atom is stored within the mitochondrial matrix. Well, no, it is not stored, it is expelled as CO2 along with all the other CO2 produced in that metabolic process. So choice three is not correct. So that leaves out to C one and three. And then finally, statement four says the third carbon atom is removed during the decarboxylate process. And this is correct, we know it's removed and that process, that chemical reaction is a decarboxylate reaction. So our correct answers here are then we can eliminate choice A one only. And our correct answer is choice D. And these statements about what happens to the third carbon atom in the conversion of pyruvate to acetyl coa are correct statements are to D statements one and four. See you in the next video

When pyruvate is used to form acetyl CoA, the product has only two carbon atoms. What happened to the third carbon?

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Key Concepts

Pyruvate Decarboxylation

Acetyl CoA

Carbon Loss in Metabolism