Amino acids and proteins, denaturation and
coagulation. Top: Three of the 20-odd amino
acids important in food. Each amino acid has
a common end including an amino (NH 2 )
group, by which amino acids bond to each
other into long chains called proteins, and a
variable end or “side group” that can form
different kinds of bonds with other amino
acids. Center: A chain of amino acids shown
schematically, with some of the side groups
projecting from the chain. The amino acid
chain can fold back on itself, and some of the
side groups form bonds with each other to
hold the chain in a folded shape. Bottom: