Need some clues

Those who post threads in here most are desperate and helpless, so am I.

Recently I am working on Respiration Project + Assignment.

The 1st project is working pyruvate molecules with radioactive carbon. Then they all incubated with all components of Krebs cycle long enough for 1 turn. Then I need to explain why the CO2 produced only one third of it is radioactive?

So, I decide to start with Glycolysis Process until oxidative-decarboxylation of pyruvate because there's where the CO2 is released before entering Krebs Cycle, am I making a good start?

My another question is imagine a starving cell reached the stage where every bit of its ATP was depleted and converted to ADP + phosphate. If the cell were placed in fresh nutrien broth at this point, will it recover and survive?

My mind is totally blank for this question, so I just need some clues where should I start with and what is the purpose of this question, the rest I'll work for myself. Thanks in advance.