Tag: Zwitterions

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.

Amino acids have surprisingly high melting points, often exceeding 200°C, which is due to their zwitterionic structure in the solid state. To comprehend what can dissolve amino acids, one must first grasp that this internal salt-like structure dictates their behavior with different solvent types based on the principle of 'like dissolves like.'

While most amino acids are neutral at physiological pH, a small but important group carries a negative charge. To understand **why are amino acids negative**, we must first explore their chemical structure and the critical role of pH, a key consideration for a balanced nutrition diet.