<prompt> Cereal protein is deficient in which amino acidLeucineLysinePhenylalanineTryptophan  <response>: Ans. is b i.e., Lysine Supplementary action of proteins Cereals are deficient in essential amino acid Lysine threonine. Pulses are deficient in essential amino acid Methionine. So if cereals are eaten with pulses, their proteins complement each other provide a more balanced and complete protein intake. 