Proteins play a major role in ensuring your health well being. There are innumerable functions of proteins in the body. Well, the primary functions of proteins include building and repairing of body tissues, regulation of body processes and formation of enzymes and hormones.
Enzymesare proteins that facilitate chemical reactions without being changed in the process. The inactive form of an enzyme is called a proenzyme. Hormones (chemical messengers) are proteins that travel to one or more specific target tissues or organs, and many have important regulatory functions.Insulin, for example, plays a key role in regulating the amount ofglucosein the blood.
Control of growth and differentiation- proteins can be critical to the control of growth, cell differentiation and expression of DNA. For example,repressor proteinsmay bind to specific segments of DNA, preventing expression and thus the formation of the product of that DNA segment. Also, many hormones and growth factors that regulate cell function, such asinsulinorthyroid stimulating hormoneare proteins.
Hormonal Proteins- are messenger proteins which help to coordinate certain bodily activities. Examples include insulin, oxytocin, and somatotropin. Insulin regulates glucose metabolism by controlling the blood-sugar concentration. Oxytocin stimulates contractions in females during childbirth. Somatotropin is a growth hormone that stimulates protein production in muscle cells.
Plasma membrane proteins have a variety of functions. (A) Schematic drawing of a typical antibody molecule. The protein is composed of four polypeptide chains (two identical heavy chains and two identical and smaller light chains) held together by disulfide bonds. Each chain is made up of several different domains, here shaded either blue or gray. The antigen-binding site is formed where a heavy chain variable domain (VH) and a light chain variable domain (VL) come close together. These are the domains that differ most in their sequence and structure in different antibodies.
Proteins are also abundant withinbiological membranes. Many cellular receptors, channels, and pumps are bound to membranes. Since these proteins span across a nonpolar environment, many of their residues facing this environment are also nonpolar, allowing more favorable interactions to occur. Both channels and pumps are involved in the regulation of fluids and ions within and outside the cell.
Controls Cell Functions: The cells in our body performed many different functions and at different times. Enzymes, a type of protein, determine which function and when it occurs. Enzymes control or regulated the various chemical reactions that lead to a particular function. Without enzymes controlling the process, there would be no order and chaos would ensure.
Proteins as Molecular Machines: Many proteins are neither rigid nor static. They change shape, open and close, twist and turn. This ability to move lets proteins be tiny machines that can grab and release, push or pull. The animations in the related links can give you an idea of the variety of movements that proteins can make.Unique structures and shape shifting enable proteins to be astounding effective catalysts.
Metabolism— proteins mediate chemical reactions that use oxygen to burn food for energy. These pathways are complex but well studied. The related links show maps of thousands of proteins in the metabolic pathways.
Signaling—hormonesare proteins that signal between cells usually in the blood. Proteins also send signal from one nerve cell to another. Signaling pathways, however, are usually interactions among proteins within a cell.
