Absorbed amino acids are immediately available to all body cells for protein synthesis. Because all of the amino acids necessary for synthesis of a given protein must be available at the time of synthesis , it is imperative that animals have a balanced diet that contains all of the essential amino acids. Protein synthesis in many organs, including liver and skeletal muscle, is stimulated by insulin, so the increase in insulin following a meal also promotes protein synthesis during this period. However, this stimulatory effect on protein synthesis is minor compared to the effects of insulin on glucose metabolism (e.g., the rate of plasma protein production by the liver increases by only a small percentage after a meal).