In organic chemistry, "poly" means many. It is a prefix used to indicate that a molecule contains many repeating units, often referring to polymers.
Polymers and Monomers
The term "poly" is most often encountered when discussing polymers. A polymer is a large molecule (macromolecule) composed of many smaller repeating units called monomers. The "poly" prefix signifies the presence of these numerous monomer units linked together.
For example:
- A monomer is a single unit.
- A polymer is made of many of those monomer units.
Examples in Organic Chemistry
Here are a few common examples to illustrate the use of "poly" in organic chemistry:
- Polyethylene: A plastic made from many ethylene (ethene) monomers.
- Polypropylene: A plastic made from many propylene (propene) monomers.
- Polystyrene: A plastic made from many styrene monomers.
- Polypeptide: A polymer of amino acids (linked by peptide bonds), also known as a protein.
- Polysaccharide: A polymer of sugar (saccharide) molecules, such as starch and cellulose.
In each of these examples, "poly-" indicates that the substance is composed of multiple repeating units of the named monomer. The properties of the resulting polymer are often vastly different from the properties of the individual monomers.
