Chemical reaction vs chemical process

[icakeov]

Hi,
I'm hoping to get clear on some chemical nomenclature.

A "chemical reaction" is a process that involves some sort of chemical change. But a conformational change doesn't involve a chemical change, just a shape change, thus from what I understand, it cannot be termed a "chemical reaction".

Is there an "umbrella term" that conformational change falls under? Perhaps "chemical process"? But Wikipedia defines "chemical process" with: "involves a chemical reaction of some sort."

I am mainly trying to figure out what the larger group that "chemical reactions" and "processes" such as conformational change would officially fall under?

Thanks for any feedback.

 

[BvU]

Hehe, it's all physics .

 

[BillTre]

Assuming you are a talking about proteins,
some are triggered by covalent modifications, like phosphorylation of the protein at some location,
others could be due to some non-covalent ligand binding interaction at a binding site, like a substrate on an enzyme,
yet others are due to electrical changes across a membrane, like a voltage sensitive ion channel in a neuron or muscle cell.

The covalent changes would be a chemical reaction,
the electric field induced changes would not.
Ligand binding might just involve weaker interactions like hydrogen bonding. Not sure if that is considered a chemical reaction or not.

 

[icakeov]

So a conformational change can technically have instances where it can be considered to be a chemical reaction overall since some form of chemical reaction might happen along the lines?

Also, if one were to just look at the electric field change and equate it with the conformational change, would there be a "formal name" for that? I imagine calling it a "chemical process" works well, as long as it is a broader term, which would as a concept, include "electric field changes", "chemical changes", etc.

 

[BillTre]

So a conformational change can technically have instances where it can be considered to be a chemical reaction overall since some form of chemical reaction might happen along the lines?

Yes.

Also, if one were to just look at the electric field change and equate it with the conformational change, would there be a "formal name" for that?

To be clear, a voltage sensitive ion channel in a membrane can switch to a different conformation (open or closed) if the voltage changes enough. I would not equate the conformation change with the voltage change, but the voltage change triggers the conformation change. There are probably drugs and toxins that can block or interfere with the channels operations. Whether they block the conformational change or just plug the channel, I don't know.

 

[icakeov]

Super helpful! Thank you!

 

[zbikraw]

Biological (biophysical and/or biochemical changes you refer to) are described mainly as biological processes. Phosphorylation of a protein is chemical change (it is a reaction), but changes in biological material are not considered important. When you cover a metal part by protective layer (in most cases with chemical reactions in a paint layer, sometimes with chemical bonding to surface), it is termed to be a chemical processing, indepenently of nature of process. Bulk of the metallic part is not involved in a process, it remains. For example when you treat rusted surface of a steel part with phosphoric acid based anticorrosive preparation, chemical reaction on the surface changes iron oxides/hydroxides into relatively insoluble ferric phosphate. Overall process is termed as anticorrosive processing, not reaction. Removing rust from steel surface by acid treatment is refferred to be processing, but dissolving isolated rust in acid is chemical reaction. The same refers to reverse processes: dephosphorylation of protein, removing the paint by chemical media and retrieving ferric oxides from salt solutions by base (again, it is reaction).
This is technical/economical jargon, but dominates in everyday life.