Proteins

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function.

A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of adjacent amino acid residues. The sequence of amino acids in a protein is defined by the sequence of a gene, which is encoded in the genetic code. In general, the genetic code specifies 20 standard amino acids; however, in certain organisms the genetic code can include selenocysteine and—in certain archaea—pyrrolysine. Shortly after or even during synthesis, the residues in a protein are often chemically modified by posttranslational modification, which alters the physical and chemical properties, folding, stability, activity, and ultimately, the function of the proteins. Sometimes proteins have non-peptide groups attached, which can be called prosthetic groups or cofactors. Proteins can also work together to achieve a particular function, and they often associate to form stable protein complexes.

Like other biological macromolecules such as polysaccharides and nucleic acids, proteins are essential parts of organisms and participate in virtually every process within cells. Many proteins are enzymes that catalyze biochemical reactions and are vital to metabolism. Proteins also have structural or mechanical functions, such as actin and myosin in muscle and the proteins in the cytoskeleton, which form a system of scaffolding that maintains cell shape. Other proteins are important in cell signaling, immune responses, cell adhesion, and the cell cycle. Proteins are also necessary in animals' diets, since animals cannot synthesize all the amino acids they need and must obtain essential amino acids from food. Through the process of digestion, animals break down ingested protein into free amino acids that are then used in metabolism. Essentially, proteins are the "worker bees" of our bodies. they are manifestation of the base pairs of our DNA. This means that just about everything that we know as individuality can be traced back to different protein manufacturing.

Proteins may be purified from other cellular components using a variety of techniques such as ultracentrifugation, precipitation, electrophoresis, and chromatography; the advent of genetic engineering has made possible a number of methods to facilitate purification. Methods commonly used to study protein structure and function include immunohistochemistry, site-directed mutagenesis, nuclear magnetic resonance and mass spectrometry.

Proteins are biochemical compounds made up of one or more polypeptides. A polypeptide is a single polymer chain of amino acids bonded by peptide bonds between the carboxyl functional group and amino functional group.



The pictures above are common ways of showing protein structures.

This shows the molecular structure of protein.

Proteins are made from the condensation reaction of two amino acids. Proteins are a long chain of amino acids. The slightest difference in amino acids can create a difference in the coiling of the protein making its purpose entirely different. for instance, sickle cell anemia is a disorder where a part of DNA coding for a beta-globin is altered slightly, thus the protein for hemoglobin is altered and cannot bind to O2 for proper delivery throughout the body. Proteins are fragile, but hold great influence on the inner-workings of life.