Collagen synthesis is shown schematically in Figure 6.14. Steps include the following:

1. Translation on the ribosome (synthesizing the primary structure);

2. Hydroxylation of the lysine and proline side chains (still on the ribosome);

3. Release from the ribosome and addition of sugars to lysines to create procollagen;

4. Assembly of central regions into triple helices/folding of N-terminal and C-terminal ends into globular structures;

5. Export of procollagen complexes from the cytosol to the extracellular space;

6. Cleavage of N-terminal and C-terminal regions, yielding the tropocollagen triple helix;

7. Oxidation of some lysine residues to aldehyde derivatives, which cross-link with lysine residues or one another on other strands to solidify the fiber (see here).