Enzymes are formed mainly by proteins; thus, one of the essential functions of the proteins is to perform enzymatic functions. Proteins also perform various other physiological functions in the body that are non-enzymatic. These include transportation, structural, immunity, movement, nourishment, and regulation.
1. Transportation: The proteins help in the transportation of various molecules in the body. For example, hemoglobin is a protein formed of four polypeptide units. It helps to transport oxygen and carbon dioxide in the blood. This helps in the supply of oxygen and removal of carbon dioxide to and from the tissues and cells of the body.
2. Structural: The proteins actin and tubulin form cellular structures (cytoskeleton). Keratin forms the structural support for the dead cells that become fingernails and hair.
3. Immunity: Antibodies (also called immunoglobins) are also proteins that help recognize and destroy foreign pathogens in the immune system.
4. Movement: Actin and myosin are protein molecules that allow muscles to contract. This helps in the movement of the body parts.
5. Nourishment: Albumin nourishes the early development of an embryo or a seedling.
6. Regulation: The peptide hormones, such as insulin, helps in the regulation of glucose levels in the blood.
Key Points
- Proteins perform enzymatic and non-enzymatic functions.
- Proteins are formed of various polypeptide units bind together.
- Non-enzymatic protein functions include transportation of molecules, structural support, movement, immunity, nourishment, and regulation.
Key Terms
- Polypeptide: Any polymer of (same or different) amino acids joined via peptide bonds.
- Catalyze: To accelerate a process.
- Enzyme: The molecules that help in speeding up the biochemical reactions.
- Cytoskeleton: It is a network of protein fibers that provide a structural framework to the cells.