Draw the structure of the amino acid, alanine.

Proteins are the building blocks of living cells in living organism. They are polymers of amino acids. The primary structure of protein is the sequence of amino acids. The α-helix and β-sheet structure are the secondary structures. Similarly tertiary and quaternary structures also have certain weak intermolecular forces.

Amino acids are organic molecules which have two functional groups bonded on same C atoms; -NH₂ group and –COOH group.

Hence the C atom is bonded with one of the R group; two functional groups and one H atom.