(Science: amino acid) alanine is a nonessential amino acid that can be manufactured by the body from other sources as needed. Alanine is one of the simplest of the amino acids and is involved in the energy-producing breakdown of glucose. in conditions of sudden anaerobic energy need, when muscle proteins are broken down for energy, alanine acts as a carrier molecule to take the nitrogen-containing amino group to the liver to be changed to the less toxic urea, thus preventing buildup of toxic products in the muscle cells when extra energy is needed. Because the body easily constructs alanine from other sources, no deficiency state is known. Alanine is found in a wide variety of foods, but is particularly concentrated in meats. a crystalline amino acid that occurs in many proteins.Alanine is one of twenty amino acids that form a polypeptide Chain (proteins).