Proteins

What is a protein? Most people would say that proteins are required for strength and muscle building. While this is true proteins have a structural purpose as well a functional one. Proteins speed up chemical reactions, fight bacteria, tranpsort substances such as oxygen, and they build other proteins to name a few of their functions. A protein is a compound made up of amino acids arranged in a linear chain. This is known as primary structure. The amino acids interact with each other via hydrogen bonding to form secondary structure. Tertiary structure is the overall shape of the protein molecule which involves the spatial relationship of the alpha helix and the beta sheet. The next level of protein structure is quaternary structure which refers to the interaction of multiple protein subunits. Many physiological responses are the result of protein interaction such as insulin binding to its receptor in the cell membrane. Serum proteins are proteins that exist in the plasma portion of blood. Immunoglobulin G is a serum protein involved in the response of the immune system to allergens. Researchers perform what's called a protein assay to dermine protein concentrations of fluids like blood. Once the protein concentration has been determined doctors can more accurately diagnose a patient. Protein electrophoresis or gel electrophoresis is used to identify proteins by comparing samples to standards of known molecular weight. Promega and BD are well known for their protein reagents and assays.