<prompt> Most abundant aminoacid in collagen isProlineLysineThreonineGlycine  <response>: COLLAGEN Collagens are triple helices formed by amino acid chains where every third residue is glycine Gly-X-Y, with a high likelihood of proline and hydroxyproline hydroxylysine in the X and Y positions, respectively. Ref:- Review of Dermatology by Alikhan; pg num:-7 