Cellular materials are composed of four major biomolecules. The four main biomolecules are proteins, lipids, nucleic acids, and carbohydrates. The structure and function of each type biomolecule are briefly described below.
- Proteins are composed of monomers called amino acids. Amino acids are composed of a central carbon atom, an amino group, a carboxyl group, and an R-group that differentiates one amino acid from another. Proteins are accredited with being the most structure of a cell. Proteins are also found interspersed throughout the cell membrane. Here, proteins serve as channels through which particles enter and exit the cell. All enzymes are also proteins. Enzymes serve as biological catalysts for reactions.
Lipids are commonly known as “fats”. Lipids are composed of a glycerol and fatty acid chains. The cell membrane is composed of a phospholipid bilayer. Lipids serves as energy-storage units for a cell. Cholesterol and other sterols are also composed of lipids.
Nucleic acids are composed of nucleotides. Nucleotides are composed of a 5-carbon sugar (either deoxyribose or ribose), a phosphate group, and a nitrogen base. Nucleic acids are responsible for housing all genetic information within a cell. Both RNA (ribose nucleic acid) and DNA (deoxyribose nucleic acid) are composed of nucleic acids.
Carbohydrates are composed of monosaccharides. Monosaccharides are largely composed of the atom carbon. In cells, carbohydrates serve as an energy resource. Carbohydrates, such as chitin and cellulose, also provide structure in the cell walls of fungi and plants.