What do the amino acids tyr, asn, and thr have in common?

The given three amino acids are polar in nature.

Explanation:

The structure of amino acid is generally composed of four parts:

1. Carboxylic group

2. Amino group

3. Hydrogen atom

5. Alkyl or Aryl group

The central carbon atom also known as alpha carbon which is surrounded by amino group on one side, H atom on top, Amino group on right side and Alkyl or Aryl group on down side.

The R group given amino acids are as,

Tyr = - CH₂-Ph-OH

Asn = - CH₂-COO-NH₂

Thr = - CH (OH) - CH₃

Hence, due to presence of Hydroxyl groups and Amine groups on Alkyl or Ary l chain the given three amino acids get polar in nature.