Assertion (A): An optically active amino acid | vedclass

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(C) Amino acids contain both acidic $(-COOH)$ and basic $(-NH_2)$ groups.In an acidic medium (low $pH$),the $-NH_2$ group accepts a proton to form a c

Vedclass · Accepted Answer

$A$ is correct,$R$ is wrong

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(C) Amino acids contain both acidic $(-COOH)$ and basic $(-NH_2)$ groups.In an acidic medium (low $pH$),the $-NH_2$ group accepts a proton to form a cation $(R-CH(NH_3^+)-COOH)$.In a basic medium (high $pH$),the $-COOH$ group loses a proton to form an anion $(R-CH(NH_2)-COO^-)$.At the isoelectric point,they exist as a zwitterion $(R-CH(NH_3^+)-COO^-)$.Thus,the assertion is correct.However,the reason states that they exist as an anionic form in acidic medium and a cationic form in basic medium,which is the reverse of the actual chemical behavior.Therefore,the reason is wrong.

List-$I$ (Amino acid)	List-$II$ (Positive reaction/Test for functional group present in side chain of amino acid)
$A$. Glutamine	$I$. Hinsberg's test
$B$. Lysine	$II$. Neutral $FeCl_3$ test
$C$. Tyrosine	$III$. Ceric ammonium nitrate test
$D$. Serine	$IV$. Hoffman bromamide degradation

Assertion $(A)$: An optically active amino acid can exist in three forms depending on the $pH$ of the solution.
Reason $(R)$: Amino acids contain both acidic and basic groups; they exist as a zwitterion in aqueous medium,anionic form in basic medium,and cationic form in acidic medium.

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Assertion $(A)$: An optically active amino acid can exist in three forms depending on the $pH$ of the solution.Reason $(R)$: Amino acids contain both acidic and basic groups; they exist as a zwitterion in aqueous medium,anionic form in basic medium,and cationic form in acidic medium.