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

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(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

Vedclass · Answer

(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.

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.

Similar Questions

The number of peptide bonds in the compound is:

Amide group is present in

Which amino acid does not contain a chiral centre?

The number of amino acids and number of peptide bonds in a linear tetrapeptide (made of different amino acids) are respectively

The correct structure of Rhumann's Purple,the compound formed in the reaction of ninhydrin with proteins is :

Vedclass Test Series

Exam Paper Generator

Online Exam Module

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.