Physiological pH Q's...

[D.D.S.]

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Hi, how do I figure out if a side chain of an amino acid is protonated or not at certain pH's without knowing the pKa/Ka's of the groups??

At low ph i understand, since their is a high concentration of H+, the side chains will be protonated.

At high ph, since there is a low amount of H+, is everything going to be unprotonated?

At physiological pH??

Thanks in advance!

 

[BenignDMD]

if ph < pk you protonate.

The carboxyl group will be unprotonated (pk~2.5) and the amino group protonated (pk~9.5) at phys. ph (~7.4).