The defining feature of an amino acid is its side chain (at top, blue circle; below, all colored circles). When connected together by a series of peptide bonds, amino acids form a polypeptide ...

Each of the 20 amino acids has a specific side chain, known as an R group, that is also attached to the α carbon. The R groups have a variety of shapes, sizes, charges, and reactivities.

Fourteen years ago, the older drug cousin of semaglutide (Ozempic and Wegovy) came onto the market. The drug, liraglutide ... they mostly have the same side effects. The most common are a range ...