Citric Acid Cycle -matching carbons

[jenzao]

Citric Acid Cycle --matching carbons

Which glucose carbons are pyruvate carbons from? I've been trying to get this for hours. please help.. Also how do you trace carbons along the ciric acid cycle?

 

[Renge Ishyo]

Each pyruvate is a 3 carbon molecule and glucose is a 6 carbon molecule. Therefore, half of the carbons in a glucose molecule go to each of the two pyruvate molecules. The step where the molecule is cut in half I believe is the step where fructose-1,6-bisphosphate is cleaved by aldolase so you should be able to see which carbons go where by analyzing the result of that step. If you want to track the carbons, the easiest thing to do is to just number them on each step of the pathway.

 

[Blueshift5]

The pyruvate carbons come from the glucose carbons that enter the citric acid cycle through the conversion of pyruvate to acetyl-CoA. This happens in the cytoplasm during the process of glycolysis.

To trace carbons along the citric acid cycle, you can follow the pathway of acetyl-CoA as it enters the cycle and is converted to citrate. As citrate goes through various reactions, the carbons are rearranged and eventually released as CO2. The remaining carbons are then used to form ATP and other molecules. The key is to keep track of the number of carbons in each molecule and how they change throughout the cycle. You can also use isotopic labeling techniques to track the movement of specific carbons in the cycle.