Cables and Nets of Collagen
Three chains of collagen twist around each other into a triple helix that forms strong cables. Some of the cables have extra "tails" that wind around each other in a regular way. These different forms of collagen (along with other proteins) form sheets, like a tough net, that support the organs in your body (including your skin - did you know that your skin is an organ too?).
(clickable 3-D image of collagen triple helix)
When people get older, the collagen that supports their skin breaks down some, and wrinkles form. Some people who want to look younger get collagen injected under their skin to make their wrinkles go away for a while. Ouch!
If you cook the collagen from animal bones (and skin too), and remove all of the extra stuff (like minerals), the chains unwind and get all tangled up. (When this happens to a protein, we say it's denatured.) When it's purified and cleaned up, guess what it is? Gelatin! You might not know that gelatin comes from animals, but it does. Those tangled-up chains of collagen soak up water like crazy, and traps it there in a gel. You can buy plain gelatin that doesn't taste like much, but the stuff you make jigglers out of has a bunch of sugar and flavors added to make it taste yummy.