Question

if glucose is fully labelled with 14c (a radioisotope of carbon), what molecule will become radioactive as glycolysis and the citric acid cycle are completed? i dont know yet atp nadh carbon dioxide water

Explanation:

Glucose is a six - carbon molecule. During glycolysis, it is broken down into two three - carbon pyruvate molecules. Pyruvate then enters the citric acid cycle. In the citric acid cycle, the carbon atoms of pyruvate are oxidized and released as carbon dioxide. Since glucose is labeled with \(^{14}C\) (radioactive carbon), through the processes of glycolysis and the citric acid cycle, the radioactive carbon will end up in carbon dioxide. ATP is a high - energy molecule produced during these processes, but it does not incorporate the carbon atoms from glucose in a way that would retain the radioactive label in its structure. NADH is an electron carrier, and while it is involved in redox reactions in these pathways, the carbon from glucose is not a part of its structure in a way that would have the radioactive carbon. Water is produced in the electron transport chain (not directly from the carbon of glucose in the way described for the question).

Answer:

Carbon dioxide