Fermentation question

[chiddler]

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I actually misunderstood the answer, picked it, and turned out to be correct. Bittersweet feeling. I am using 2010's TPR's bio book. The following is the question then the answer:

Q: In lactic acid fermentation, pyruvic acid serves as an:

A: Electron acceptor for oxidation of NADH.

What I do not understand is that in the PDC reaction, seen here, NAD+ is reduced because it accepts an electron. Not oxidized like the answer suggests. Pyruvate doesn't function as an electron acceptor for NADH at all.

Is this a book error? Or am I missing something.

Thanks very much!

 

[wish2bMD]

The pyruvate decarboxylase reaction is not the same as fermentation and actually has nothing to do with fermentation at all. PDC is part of oxidative phosphorylation. In fermentation, NADH is converted back into NAD+ and in order to be oxidized, pyruvic acid is reduced (accepts e-).

 

[chiddler]

The pyruvate decarboxylase reaction is not the same as fermentation and actually has nothing to do with fermentation at all. PDC is part of oxidative phosphorylation. In fermentation, NADH is converted back into NAD+ and in order to be oxidized, pyruvic acid is reduced (accepts e-).

OF COURSE!

what a stupid error. thanks very much.

 

[Erythropoietin]

Yes the above explanation is correct; it is the pyruvate that gets reduced to pyruvic acid, which is probably a minor detail.