Because the ninhydrin test produces the same purple color for all amino acids except for proline, it cannot be used to identify all other 19 amino acids.
Amino acids are the molecules from which proteins are made.
Amino acids contain an alpha amino and carboxyl group, with a side chain group attached.
The ninhydrin test is used to test for the presence of amino acids generally and for proline specifically.
Since the ninhydrin test produces the same purple color for all amino acids except for proline, it cannot be used to identify all other 19 amino acids.
Learn more about amino acids at: https://brainly.com/question/2526971
