Expert: Walter Hintz - 8/12/2009

Question
The krebs cycle turns pyruvic acid a 3 carbon molecule into CO2 a single carbon molecule. Why has the cell evolved to carry out this chemistry using molecules containing up to 6 carbons?

I have been given a question in biochem that I have no answer for and I have no idea where to begin

The krebs cycle turns pyruvic acid a 3 carbon molecule into CO2 a single carbon molecule. Why has the cell evolved to carry out this chemistry using molecules containing up to 6 carbons?

Answer
Hi Alexander; I have been reading your question over nd have trouble coming to a conclusion.  I can see why you are having trouble and I am afraid that my answer may not help.  You have been asked why a cell behaves as it does.  Why questions are in the realm of evolutionary biology.
Which came first; the 6 carbon sugar or the living cell.
 Why qiestions can best be answered by saying that that is how things involve and that is what works best.