Question

How does pH affect amino acid charge?

Answer 1

Protonation and deprotonation of the functional groups

Explanation:

I explained this in a duplicate question. Here is the link to that.
How does pH affect amino acid structure?

Summary of the explanation is that you look at the `pK_a` values of the carboxyl and amino groups of the generic structure. Some R groups may be protonated, so pay attention to those. Depending on the pH that your amino acid is at, certain groups may or may not be protonated.

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