Proteins essays

Proteins essays Proteins are the macromolecules of life. Discovered in 1838, proteins are recognized as a large number of superior organic compounds that make up living organisms and are essential to their functioning. The term protein comes from the Greek word for primary. Proteins have many different properties and function in a variety of ways. They can function as a building material, in teeth, bones and muscles, and they can serve as enzymes, hormones, and neurotransmitters. Its functions are the most diverse of any family. Whether found in humans like, animals, plants or in single-celled bacteria, proteins are made of units of 20 different amino acids. Proteins consist of macromolecules called polypeptides, made from monomers called amino acids. Proteins have hundreds, thousands, or sometimes even millions of these amino acids. These amino acids are made up of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. Some proteins consist of only single polypeptides. In most cases it involves two or more combined polypeptides, sometimes with other small organic molecules or metal ions. The most basic level of protein structure, called the primary structure, is the linear sequence of amino acids. Different sequences of the acids along a chain, however, affect the structure of a protein molecule in different ways. Proteins secondary structure often contains long stretched out chains of amino acids called strands that line up together to make sheets. These are called beta strands and the sheets are called beta-pleated sheets. A protein may contain either or both alpha helices and beta pleated sheets. Alpha helices and beta pleated sheets are joined by less clear structures often grouped together under the name of coil. Some small proteins may be made of coil. There are two types of proteins, fibrous and globular. The major fibrous proteins are collagen, keratin, fibrinogen, and muscle proteins. Collagen, which mak...