[omar_a1]

Maybe I'm just using a less narrow definition of quantum mechanics? I'm not referring to the specific quantum phenomena referenced in the article, but to quantum mechanics in general. In other words, since these redox steps are happening on a molecular scale, that of course quantum mechanics falls under its purview - as would anything else happening on this small of a scale.

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.

[Ultimatt]

The difference is mainly of scale, would you describe calcium signalling and calcium ionic standing waves using quantum mechanics? You could. But its not relevant or helpful to do so as that bulk effect doesn't act as a quantum system with quantum behaviours. But a single calcium ion going across a potential gradient in a cation channel does quite often require that description. This is the difference here. Physicists quite often wander into Biology and make quite wild claims without even understanding what is already well known and understood via Chemistry, and sure some of that is inherently just fronting quantum mechanics behind the scenes. But its specifically if a system depends on a quantum effect in a quantum system to understand the observed phenomena. Using numerology rather than reaction rates to describe something being a quantum system isn't good science, it's not even good/exciting/interseting speculation.

[omar_a1]

"what is already well known and understood via Chemistry, and sure some of that is inherently just fronting quantum mechanics behind the scenes."

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.