Question

Which one of the following statement is not correct?

• A. Except Glycine all other occurring $\alpha -amino$ acids are optically active
• B. $\alpha -Amino$ acids have maximum solubility at their isoelectric point
• C. A tripeptide has two peptide bonds
• D. $\alpha -Amino$ acids exist as Zwitter ions

Answer 1

Answer: (B)

$\alpha -Amino$ acids have maximum solubility at their isoelectric point

α−Amino acids have minimum solubility at their isoelectric point. At isoelectric point, they exists as as Zwitter ions. Hence, the statement shown by option B is not correct. They have no net charge. So they are less likely to be soluble in polar solvents at this pH.