Glutamine
Glutamine (symbol Gln or Q) is an α-amino acid that is used in the biosynthesis of proteins. Its side chain is similar to that of glutamic acid, except the carboxylic acid group is replaced by an amide. It is classified as a charge-neutral, polar amino acid. It is non-essential and conditionally essential in humans, meaning the body can usually synthesize sufficient amounts of it, but in some instances of stress, the body's demand for glutamine increases, and glutamine must be obtained from the diet. It is encoded by the codons CAA and CAG.
Cytochrome c
Cytochrome c has a primary structure consisting of a chain of about 100 amino acids. Many higher-order organisms possess a chain of 104 amino acids. The sequences of cytochrome c in humans is identical to that of chimpanzees (our closest relatives), but differs more from that of horses.