Here is the enhanced content for clarity and readability, incorporating the requested formatting:

Other naturally occurring polymers include proteins, nucleic acids, cellulose, and rubber.

Proteins are essential natural polymers that play a crucial role in the structure, function, and regulation of the body’s tissues and organs. They are composed of amino acids, which are organic compounds made up of nitrogen, carbon, hydrogen, and oxygen. There are 20 distinct types of amino acids that can be combined in various sequences to form a protein. The specific order of these amino acids determines each protein’s unique three-dimensional structure and, consequently, its specific function.

Nucleic acids represent another important category of natural polymers. These are complex, high-molecular-weight biochemical macromolecules that perform vital roles in all living organisms. The two primary types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA carries the genetic instructions essential for the growth, development, functioning, and reproduction of all known living organisms and many viruses. In contrast, RNA acts as a template for protein synthesis.

Cellulose is a natural polymer that serves as a fundamental component of plant cell walls. It is recognized as the most abundant organic polymer on Earth. The cellulose content in various materials varies: for instance, cotton fiber contains about 90% cellulose, wood contains approximately 40–50%, and dried hemp has around 57%. Cellulose is classified as a complex carbohydrate, or polysaccharide, comprising over 3,000 glucose units.

Rubber is another noteworthy naturally occurring polymer. It is classified as an elastomer and is primarily derived from latex, a milky colloid produced by certain plants. The extraction process involves ‘tapping’ the plants, which entails making an incision in the bark to collect the sticky, milky latex sap. This sap is then refined into usable rubber. The purified form of natural rubber is known as polyisoprene, a compound that can also be synthesized artificially. Natural rubber finds extensive use in a wide range of applications and products, either on its own or in combination with other materials.