It seems not so clear cut?
This article mentions a controversy on the topic: https://physicsworld.com/a/is-photosynthesis-quantum-ish/
This article mentions a controversy on the topic: https://physicsworld.com/a/is-photosynthesis-quantum-ish/
For instance, not factoring in steric factors (e.g. uncertainty principle) or electron tunneling in the transfer of electrons during photosynthesis or cellular respiration would probably throw off your models. Biochemists are well aware of this; you couldn't effectively understand chemistry without understanding quantum mechanics.
This is actually my main point. I'm not intending to reduce or dismiss (bio)chem through the lens of applied physics. I'm saying that anyone competent in biochem understands these properties on an intuitive level, and further understands that the root of these systems' behavior lies in quantum mechanics, even if they're not crunching wave equations on a daily basis. (That said, discussing s and p orbitals are a pretty routine part of figuring out organic reaction mechanisms.)
The field considers the quantum effects on these systems as a matter of course - as with your example about ion channel flow and caveats on bulk properties versus a single ion. There's still no question that quantum mechanics affects these systems, it's just a question of when it needs to be factored in to not throw off the calculations, and when the scale is large enough that its effects can be considered negligible.