At pH = 4, glycine exists as

Options

A. `H_(3)overset(+)(N)-CH_(2)-COO^(-)`
B. `H_(3)overset(+)(N)-CH_(2)-COOH`
C. `H_(2)N-CH_(2)-COOH`
D. `H_(2)N-CH_(2)-COO^(-)`

Answer

B

Explanation

At pH = 4 (i.e. acidic medium), an amphoteric Zqitter ion structure changes into cation when an acid is added to it.
`underset(""^(o+)NH_(3))underset("|")(R )-CH-COO^(Ө)+H^(+)rarr underset(""^(o+)NH_(3))underset("|")(R )-CH-COOH`