BIOMOLECULES AND ENZYMES

Detailed explanation-1: -The isoelectric point (pI) is the pH value at which the molecule carries no electrical charge. The concept is particularly important for zwitterionic molecules such as amino acids, peptides, and proteins. For an amino acid, the isoelectric point is the average of pKa values for the amine and the carboxyl group.

Detailed explanation-2: -The isoelectric point of an amino acid is the pH at which the amino acid has a neutral charge.

Detailed explanation-3: -1). When an amino acid contains both a plus and a minus charge in the “backbone", it is called a zwitterion and has an overall neutral charge. The zwitterion of an amino acid exists at a pH equal to the isoelectric point.

Detailed explanation-4: -The isoelectric point (pI) of a protein is defined as the pH at which the net charge of a protein molecule is zero. Accordingly, proteins are positively charged at a pH below their pI and negatively charged at a pH above their pI.