1 Collagen is most commonly found within the body in the skin, bones and connective tissues. 2  The word collagen is derived from the Greek kolla, meaning glue.  Collagen gives the skin its strength and structure, and also plays a role in the replacement of dead skin cells.
sieve A sieve is a mesh strainer used to separate lumps and clumps from the fine material. Sieves are handy for everything from sifting flour to prospecting for gold â anything where you need to separate the big from the small. If youâre an archaeologist, you've probably used various sorts of sifters and shakers to sieve through the soil to recover even the tiniest artifacts.
Like the pores of activated carbon, these pores serve as a screen (sieve) by allowing only the molecules of a certain diameter to be absorbed or pass through. Molecular sieves are used in drying and deodorizing, in cracking of petroleum, and in filtering water and other liquids and gases. In some applications, they are loaded with chemicals that do not participate in a reaction until forced out from the sieve by high temperature or more readily absorbed substances.