Check the machinery before you blame ATP
- The idea
- Predict
- See it
- Why
- Check
The idea
“If a cell can't do something, it must be low on ATP. If it does a lot, it has lots of energy.”
ATP powers most of what cells do, so low energy seems like a safe guess for any failure. A full tank won't help a car with a broken fuel pump.
The short version
The mistake: If a cell can't do something, it must be low on ATP. If it does a lot, it has lots of energy.
What's actually true: Each process needs its own parts, like pumps and enzymes. One missing or blocked part can stop it even with plenty of ATP.
- Cells remake ATP about as fast as they use it, so levels usually hold steady. A real shortage slows pumping, protein synthesis and movement at once.
- Each process needs its own parts, like a pump, receptor, enzyme or organelle. If one process fails and ATP is normal, look for a part only that process uses.
- Many mitochondria means a cell uses a lot of energy. What it makes depends on other parts, like rough ER for exported proteins.
On the exam: Before you blame ATP, measure it. If it's normal, find the part that broke.