The organic molecules that living organisms are made up of are divided into 4 different types. These are carbohydrates, lipids, proteins, and nucleic acids.
Organic molecules are quite complex and can form chains or polymers, a state that they are normally found in, that are thousands of simpler units linked together.
The single units or monomers that link together to form polymers are different in the case of carbohydrates, lipids, proteins, and nucleic acids.
The monomer in the case of carbohydrates is called monosaccharide. For lipids, the monomer is called glycerol or a fatty acid. For proteins the monomer is an amino acid and for nucleic acids the monomer is a nucleotide.