The fatty acids may be saturated or unsaturated. Cholesterol is found only in animal tissue. A phospholipid contains 2 fatty acids an one phosphate connected to a glycerol molecule. Functions in movement, transport, fighting infection. Contains the carboxyl and amino groups.
Monomers are amino acids.
There are over 20 amino acids. The order and number of the amino acids dictates the type of protein. Enzymes are one of the most important types of proteins. Enzymes lower the activation energy of the reaction. The enzyme contains a site on its molecule called the active site.