How does a cell know if O2 is being diffused with it or CO2?

Question

I just read about diffusion today and I want to know how does a cell(plasma membrane to be more specific)know if O2 is being passing through it or CO2?

In: Biology

Answer 1

My vague understanding is this:
Diffusion occurs because both oxygen and CO2 naturally balances with itself. So oxygen tends to spread to where there is less oxygen (outside to inside of cell) as with CO2 except there is more CO2 inside the cell then outside of it.

As far how a cell “knows”, not sure but the cell doesn’t actively do this. It’s passively doing it due to physics/chemistry.

I’m no expert so feel free to correct me friends.