Question

Which of the following amino acid is neutral?

• A. Glycine
• B. Aspartic acid
• C. Lysine
• D. Arginine

Answer 1

The correct option is A

Glycine

Explanation for correct option

(A) Glycine

Amino acid

• Amino acids are chemical molecules that contain amino $\left(-{\mathrm{NH}}_2\right)$ and carboxylic acid $\left(-\mathrm{COOH}\right)$ functional groups, as well as a side chain specific to each amino acid.
• The general chemical formula for amino acids is $\mathrm{R}-\mathrm{CH}\left({\mathrm{NH}}_2\right)-\mathrm{COOH}(\mathrm{R}=\mathrm{side}\mathrm{chain})$.
• Amino acids are classified as neutral, acidic, or basic based on the number of amino groups and carboxylic groups.
• Amino acids, often known as protein building blocks, are chemicals that serve several important roles in the body.
• Protein-rich foods like meat, fish, and soybeans are high in amino acids.

Glycine

• The chemical formula of Glycine is ${\mathrm{H}}_2\mathrm{N}-{\mathrm{CH}}_2-\mathrm{COOH}$
• Glycine contains an equal number of acidic $\left(-\mathrm{COOH}\right)$ and basic $\left(-{\mathrm{NH}}_2\right)$ groups.
• It is a neutral amino acid.

Explanation for incorrect options

(B) Aspartic acid

• The chemical formula of Aspartic acid is ${\mathrm{C}}_4{\mathrm{H}}_7{\mathrm{NO}}_4$.
• Aspartic acid is an acidic amino acid.

(C) Lysine

• The chemical formula of Lysine is ${\mathrm{C}}_6{\mathrm{H}}_{14}{\mathrm{N}}_2{\mathrm{O}}_2$.
• Lysine is a basic amino acid.

(D) Arginine

• The chemical formula of Arginine is ${\mathrm{C}}_6{\mathrm{H}}_{14}{\mathrm{N}}_4{\mathrm{O}}_2$.
• Arginine is a basic amino acid.

Therefore, the correct option is (A) Glycine.