Tag: R groups

Over 500 different amino acids are found in nature, yet only 20 are commonly encoded in the universal genetic code to build proteins. Each of these 20 amino acids is distinct due to a variable side chain, or R-group, attached to a common core structure. This unique structural feature is the key differentiator, influencing the chemical behavior and function of each amino acid within a protein.

There are 20 standard amino acids that serve as the fundamental building blocks for all proteins found in living organisms. The profound role of amino acids in proteins lies in how their precise sequence and unique properties dictate a protein's final shape and biological function.

At physiological pH, which is approximately 7.4, only five of the 20 standard amino acids possess a net charge on their side chain. This critical property, determined by the chemical nature of their R-groups, dictates their role in protein structure, function, and interactions with other molecules, explaining what amino acids have a charge in a biological context.