Question

In: Chemistry

To calculate the isoelectric point of amino acids having other ionizable functional groups, we must also...

To calculate the isoelectric point of amino acids having other ionizable functional groups, we must also take into account the

pKa

of the additional functional group in the side chain.

For an acidic amino acid (one with an additional acidic OH group): For a basic amino acid (one with an additional basic NH group):
pI =

pKa

(

α

-COOH) +

pKa

(side COOH)

2

pI =

pKa

(

α

-NH3+) +

pKa

(side NH)

2


Indicate which

pKa

values must be used to calculate the pI of the following amino acids: [1] aspartic acid; [2] arginine; [3] lysine. Be sure to answer all parts.

Amino Acid

pKa

(

α

group)

pKa

(side chain group)
aspartic acid
arginine
lysine

Solutions

Expert Solution

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