The primary difference between the amino acids commonly found in proteins is in their:

A) R or variable groups
B) number of potassium groups
C) number of phosphate groups
D) number of carbonyl groups
E) number of asymmetric carbons

Asymmetric Carbons

Asymmetric carbons are carbon atoms bonded to four different atoms or groups, leading to molecules that can exist in non-superimposable mirror images, or enantiomers.

Variable Groups

Identifiable segments or categories within a study or dataset that are manipulated or categorized for analysis.