Firmness and Elasticity
Collagen is one of the principal proteins that form the structure holding the skin together in the Extra Cellular Structural Matrix (ECM).
Collagen Synthesis repairs and replaces damaged collagen structures/fibers.
Collagenase/Matrix Metalloproteinase (MMP-1) is a protein/enzyme that important for breaking down damaged or worn structures to make way for immune cells to come in to prep collagen synthesis to take over repairing the damaged structures. MMPs are important to the natural physiological process because they break down damaged or worn structural proteins, promote wound healing and clear pathways for immune cells to travel to infected areas. 
When there is overproduction of MMP-1 (collagenase), the breakdown of collagen occurs faster than it is synthesized. Collagenase, an enzyme also known as Matrix Metalloproteinases (MMP’s), accumulates due to overproduction caused by genetic or environmental factors. Collagenase creates breakdown of both unhealthy and healthy collagen fibers faster than the collagen fibers can be synthesized.
In healthy skin, there is a balance of MMP-1 and collagen, so redundant and damaged collagen is degraded at nearly the same speed as it is synthesized.
When you are younger, collagen synthesis predominates collagen degradation (collagenase production) and this is what gives you a youthful appearance. Even with healthy aging as you get older, the breakdown of collagen fibers found in the extra cellular matrix becomes more dominant than the synthesis of collagen.
Those with a high-risk genetic variance in this category will be predisposed to accelerated collagen breakdown and halted collagen synthesis. You will have an increased expression of the MMP-1 protein and you must protect yourself from its damaging effects by avoiding lifestyle choices that promote them and finding ways to inhibit them.
Examples of things that increase your MMPs are cigarette smoke, sugary foods, UV irradiation from sunlight (photo-aging), inflammation, glycation and oxidation. It is beneficial to find a lifestyle that involves foods, supplements, topical solutions and a proper environment that will increase collagen synthesis and inhibit collagen degradation. Senescence (when cells can no longer divide and become irreversibly dormant) happens with severe DNA damage and oxidative stress and causes increased MMP production. Please see Sun Damage and Free Radical pages for more information. One way of increasing collagen synthesis is by improving mitochondrial function.