The building blocks of starch are glucose monomers. Starch is a complex carbohydrate that is exclusively produced by plants as storage for glucose molecules.
In biochemistry, carbohydrates are considered as one of the biomolecules that are essential to an organism's survival. Carbohydrates are the primary sources of biological fuels that drive cellular processes such as respiration. Aside from carbohydrates, other vital organic molecules include lipids, proteins and nucleic acids. With the exception of lipids, carbohydrates, proteins and nucleic acids are further classified as macromolecules, or organic compounds that are synthesized by using building blocks known as "monomers." Amino acids are the building blocks of proteins, nucleotides form the fundamental units of nucleic acids and monosaccharides are the monomers of carbohydrates.
Monosaccharides consist of the simplest sugar molecules, while disaccharides are formed when two monosaccharides covalently bond together. Complex carbohydrates, referred to as "polysaccharides," function for the storage of food, reinforcement for the structures of plant and sources of energy. The starch polysaccharide is composed of a long chain of glucose molecules chemically joined by 1-4 alpha glycosidic bonds. Glucose, which also serves as the building block for other polysaccharides such as glycogen, chitin and cellulose, has the molecular formula C6H12O6. It is the most abundant monosaccharide and one of the chief products of photosynthesis.