There isn't a single formula that represents all amino acids, as they all have a common structure but differ in their side chain (R group). However, here's a general formula representing the basic structure of an amino acid:

R - CH(NH₂) - COOH

Where:

* R represents the side chain or R group, which varies between different amino acids and gives each amino acid its unique properties.

* CH(NH₂) - COOH represents the common core structure of all amino acids, consisting of:

* -NH₂ (amino group)

* -COOH (carboxyl group)

* -CH (central carbon atom)

This general formula helps understand the shared structure of all amino acids. The diversity in their side chains (R groups) gives rise to the 20 standard amino acids found in proteins.