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QJEEAdv20Chbf94: JEE Advanced 2020 Chemistry - Class 12 JEEAdv20Chbf94 Solution: The structure of a peptide is given below. If the absolute…
The structure of a peptide is given below.
If the absolute values of the net charge of the peptide at , , and are , and , respectively, then what is ?
If the absolute values of the net charge of the peptide at , , and are , and , respectively, then what is ?
Step-by-Step Verified Solution
At pH = 2,
There are two NH2 group, and + 1 charge on each group because all amino groups exist in the form of NH .
Therefore, |Z1| = 2.
At pH = 6,
NH2 of lysine (+ 1) (pH = 9.47) and COOH ( 1) of glutamic (pH = 3.08) acid, so because of dipolar ion exists, therefore |Z2| = 0.
At pH = 11,
COOH of glutamic acid has ( 1), COOH of lysine ( 1) and OH of phenol ( 1).
Therefore, |Z3| = | 3| = 3 (All COOH and OH exist in the form of COO and O ).
|Z1| + |Z2| + |Z3| = 2 + 0 + 3 = 5
There are two NH2 group, and + 1 charge on each group because all amino groups exist in the form of NH .
Therefore, |Z1| = 2.
At pH = 6,
NH2 of lysine (+ 1) (pH = 9.47) and COOH ( 1) of glutamic (pH = 3.08) acid, so because of dipolar ion exists, therefore |Z2| = 0.
At pH = 11,
COOH of glutamic acid has ( 1), COOH of lysine ( 1) and OH of phenol ( 1).
Therefore, |Z3| = | 3| = 3 (All COOH and OH exist in the form of COO and O ).
|Z1| + |Z2| + |Z3| = 2 + 0 + 3 = 5