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Specialty Chemistry Forums => Biochemistry and Chemical Biology Forum => Topic started by: Traumatic Acid on March 21, 2018, 02:36:17 AM

Title: Correct calculations? Net charge of polypeptide.
Post by: Traumatic Acid on March 21, 2018, 02:36:17 AM

Hi all.
I have attached an image of my calculations of the net charge of a small poly peptide chain.
The amino acids in question are; Lysine, Tyrosine, and Glutamic acid. I determined the net charge of the polypeptide chain at pH8, to be 0.
If someone can confirm this that would be great. Attached (Hopefully) is an image of my personal calculations.

Thanks in advance.  :)

Title: Re: Correct calculations? Net charge of polypeptide.
Post by: Babcock_Hall on March 21, 2018, 10:10:42 AM

Your answer may or may not be correct, but your method is suspect.  In a peptide most of the carboxylate groups and amino groups no longer exist in that form, being part of amide bonds (more specifically, peptide bonds).