Biochemistry

Organic Compound

a chemical compound that contains carbon

Macromolecule

very large molecules that serve as the building blocks for biological systems

Monomer

a small molecule that is utilized as a chemical unit (a building block) to construct larger molecules known as polymers

Polymer

a large molecule (macromolecule) that is constructed from numerous repeating chemical units, or monomers

Macromolecules of biological importance, their constituent elements, subunit molecules (monomers), examples, and primary roles in organisms,

Macromolecule	Elements	Subunit Molecules	Examples	Roles in Organisms
Carbohydrates	C, H, O (with H:O ratio of 2:1)	Monosaccharides (e.g., glucose)	Starch, Glycogen, Cellulose	Energy source (glucose, starch, glycogen), Structural material (cellulose in plant cell walls)
Lipids	C, H, O (with less O than carbohydrates)	Fatty acids and glycerol, or fatty acids, glycerol, and phosphate group	Triglycerides (fats and oils), Phospholipids	Energy reserve (fats and oils), Electrical insulation (e.g., in the myelin sheath), Component of biological membranes (phospholipids)
Proteins	C, H, O, N (S and P also found in some types)	Amino acids (about 20 different types)	Enzymes, Haemoglobin, Collagen, Antibodies, Hormones (e.g., insulin)	Catalysis (enzymes), Transport (haemoglobin), Structure (collagen), Defence (antibodies), Regulation (hormones)
Nucleic acids	C, H, O, N, P	Nucleotides (composed of phosphate group, pentose sugar, and organic base)	DNA, RNA	Carry genetic information (DNA), Involved in protein synthesis (RNA)