When $HNO_3$ is dropped into the palm and washed with water,it turns yellow. The above yellow colour is due to:

$A$ polypeptide can be called a protein when its mass is

Which of the following one-letter symbols is used to represent aspartic acid?

Describe the term $D$ and $L$ configuration used for the amino acids with examples.

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.

Consider the following sequence for aspartic acid:
$H_3N^+-CH(COOH)-CH_2COOH \leftrightarrow{pK_1=1.88} H_3N^+-CH(COO^-)-CH_2COOH \leftrightarrow{pK_R=3.65} H_3N^+-CH(COO^-)-CH_2COO^- \leftrightarrow{pK_2=9.60} H_2N-CH(COO^-)-CH_2COO^-$
The $pI$ (isoelectric point) of aspartic acid is: