Question

Describe how the r group in each of the 20 differebt amino acids determines each amino acid's characteristics

Answer 1

The polarity and acid/base character of each R group is the main factor determining the characteristics of an amino acid.

There are four types of R groups:

• nonpolar, e.g., CH₃ in alanine

• polar, e.g., CH₂OH in serine

• acidic. e.g., CH₂COOH in aspartic acid

• basic, e.g., CH₂(CH₂)₃NH₂ in lysine

The R group determines whether an amino acid is acidic, basic, or neutral.

However, the nature of the R groups is the major factor that determines the 2° and 3° structures of polypeptides and proteins.