Category: Protein structure

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.

Every protein possesses at least three levels of structural organization, though many biologically active proteins are comprised of four distinct levels. These levels, which range from a simple amino acid sequence to complex 3D arrangements, are fundamental to determining a protein's function and properties.

Glycine is a foundational element in the body, constituting roughly one-third of collagen's total amino acid content, a much higher proportion than found in most other proteins. Understanding why glycine is common in collagen is key to appreciating the protein's remarkable properties and its importance for the integrity of our connective tissues.