Proteins Essay example -- science

ProteinsProteins atomic number 18 the macromolecules of life. Discovered in 1838, proteins ar recognised as a largish number of superior organic compounds that subscribe to up life organisms and are essential to their functioning. The term protein comes from the Greek intelligence proteies or primary. Proteins have many different properties and function in a variety of ways. They can function as a edifice material, in teeth, bones and muscles, and they can serve as enzymes, hormones, and neurotransmitters. Its functions are the closely diverse of any family. Whether found in humans, animals, plants or in single-celled bacteria, proteins are crystalize of units of 20 different amino group group 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 pr oteins consist of scarcely single polypeptides. In close to cases it involves two or more combine 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. antithetical 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 unwrap 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 fall in by less clear structures often grouped together d knowledgestairs the name of coil. Some small proteins may be made of coil. modulate is also grand. Proteins are coiled and twisted, giving it a unique human body. The shape depends on the sequence of the amino acids, which can be hydrophilic or hydrophobic. Those that are hydrophilic want contact with water and will be twisted to maximize contact. Those that are hydrophobic are twisted in such a way to minimize contact. Changing one amino acid in the polypeptide sequence can destroy this shape and make the protein function improperly if not at all. A very important function that proteins can serve are to act as catalysts. Enzymes are organic catalysts ma... ... cells their shape and as well as parts of the linkages that perplex cells together into tissues and organs. So, the sequence of amino acids in all proteins is genetically decided by the sequence of nucleotides in cellular DNA. So basically Proteins are basic constituents in all sprightliness organisms. They are complex molecules unruffled of amino acid and necessary for the chemical processes that occur in living organisms. Proteins are sometimes referred to as macromolecular polypeptides because they ar e very large molecules and because the amino acids of which they are composed are joined by peptide bonds. The wide majority of the proteins found in living organisms are composed of further 20 different kinds of amino acids, repeated many times and set up together in a particular order. Each type of protein has its own unique sequence of amino acids. Also each protein makes every living organism different. Bibliography 1. Proteins, Lexicon Universal Encyclopedia, 1989 Volume 15, pg.576. 2. www.biotech.imcb.edu.com 3. http//www.faseb.org/protein.html 4. Proteins. SceinceDaily.2000 www.sceincedaily.com 5. Proteins. Britannica Online 2000 www.britanncia.com