All of the following are essential aminoacids except

Ans. is 'c' i.e. Alanine Nutritionally, amino acids are of two types: a. Essential amino acids: These cannot be synthesized by the body and must be obtained from the diet in order for normal protein synthesis to occur.b. Non essential amino acids: These can be synthesized in sufficient amounts from the intermediates of metabolism or as in case of cysteine & tyrosine from essential amino acids. They are only nutritionally non-essential but biologically essential.There is also a third group of semi essential amino acids. These are synthesized by body at rates inadequate to support growth of children, e.g. Arginine & Histidine.Remember all 20 amino acids are biologically essentialAmino acids can be classified as glucogenic or ketogenic based on intermediates produced during their catabolism.Classification of amino acids EssentialSemi essentialNonessentialGlucogenicMethionineThreonineValineArginineHistidineAlanineAsparagineAspartateCysteineGlutamateGlutamineGlycineProlineSerineGlucogenic andKetogenicIsoleucinePhenylalanineTryptophan TyrosineKetogenicLeucineLysine Two amino acids: Hydroxyproline and hydroxylysine are not necessary for protein synthesis but formed during post translational processing of collagen.