cellular respiration?

Question

what is the purpose of decarboxylation and kreb's cycle reactions in aerobic respiration?

Answer 1

http://en.wikipedia.org/wiki/Cellular_respiration

Answer 2

The process of glycolysis that breaks down glucose to pyruvate yields only 2 ATP. However, if glucose is oxidized all the way to CO2 and H2O through the decarboxylation and Krebs Cycle, the yield of ATP is 36 total.

The decarboxylation step breaks down pyruvate to acetyl-CoA, which enters the Krebs Cycle. Each cycle converts the two carbon in acetyl-CoA to 2 molecules of CO2.