16.4 Polymers and Biopolymers
Polymers – A large molecule made up of connected repeating smaller molecules (called monomers)
Copolymer – A polymer composed of more than one different monomers
Addition Polymers
Typically made from alkene monomers
Condensation Polymers
Made via condensation reactions between monomers which produce a small molecule, usually water.
Proteins
A protein is a condensation polymer of amino acid monomers. There are 20 different amino acids in humans (and most organisms) making a high degree of variability possible. Proteins can have structural roles in and around cells but many proteins, called enzymes, are responsible for catalyzing one of the many chemical reactions that take place in living organisms.
Carbohydrates
Carbohydrates include what we commonly call “sugars.” Carbohydrates can exist as monomers (called monosaccharides) such as glucose, dimers called dissacharides such as sucrose (table sugar—made of glucose and fructose monomers) and as much larger polymers such as starch (shown below) and glycogen which are used for glucose storage in plants and animals respectively.
Nucleic Acids
DNA and RNA are polymers of nucleic acid monomers. DNA exists in a double helix structure in which two polymeric strands are associated with each other through numerous instances of hydrogen bonding (indicated in red below). Nucleic acids provide a mechanim for storing the genetic information of a cell/organism and using that information to create the proteins necessary for the life of the cell/organism.
