The general formula of amino acid is H2N-(CH)R-COOH. If R is replaced by CH3 then the amino acid is called ..........

The amino acid is called Alanine.

Explanation:

Alanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. In the case of alanine, the "R" group (which determines the specific properties of the amino acid) is a methyl group (−CH3). This substitution is what distinguishes alanine from other amino acids. The general structure of alanine can be represented as H2N−C(CH3)−COOH, where the central carbon (C) is attached to the amine group (−NH2), the carboxylic acid group (−COOH), and the methyl group (−CH3).

In summary, when R is replaced by CH3 in the general amino acid formula, the resulting amino acid is alanine.