What happens to carbon and oxygen when glucose breaks down

When glucose is broken down, it is converted to Pyruvate and acetyl-CoA. Acetyl-CoA is then put in Electron Transport Chain (ETC).

Long story short, Oxygen is used to make ATP (energy) in ETC, and a by product of ETC, is CO2 and H2O.

If you are referring to the Carbon in the glucose, it is used to make ATP (energy).

Hope that helps:)
Hamza

When you break down Glucose, your products will be H2O and CO2 with a net increase in energy