the main steps in collagen biosynthesis are transcription and translation , hydroxylations of prolyl and lysyl residues , glycosylations of hydroxylysyl residues , chain association and disulphide bonding , triple helix formation , secretion of procollagen into the extracellular matrix , conversion of procollagen into collagen , specific aggregation of collagen molecules and crosslink formation .
C0033235
procollagen
C0009325
collagen