A prosthetic group is a non-protein (non-amino acid) component of a conjugated protein. The prosthetic group may be organic (such as a vitamin, sugar, or lipid) or inorganic (such as a metal ion). Prosthetic groups usually bond covalently to their protein. They often play an important role in the function of many proteins such as enzymes. A good example of a prosthetic group is the heme group in hemoglobin. A protein without its prosthetic group is called an apoprotein, while a protein combined with its prosthetic group is called a holoprotein. Phenylalanine is one of the standard amino acids. ... A conjugated protein is a protein that functions in interaction with other chemical groups attached by covalent bonds, or by weak interactions. ... Benzene is the simplest of the arenes, a family of organic compounds An organic compound is any member of a large class of chemical compounds whose molecules contain carbon and hydrogen; therefore, carbides, carbonates, carbon oxides and elementary carbon are not organic (see below for more on the definition controversy... Retinol (Vitamin A) For the record label, see Vitamin Records Vitamins are nutrients required in very small amounts for essential metabolic reactions in the body. ... Magnification of grains of sugar, showing their monoclinic hemihedral crystalline structure. ... A polyunsaturated triglyceride. ... Inorganic chemistry is the branch of chemistry concerned with the properties and reactions of inorganic compounds. ... Hot metal work from a blacksmith In chemistry, a metal (Greek: Metallon) is an element that readily loses electrons to form positive ions (cations) and has metallic bonds between metal atoms. ... Covalent bonding is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms. ... Neuraminidase ribbon diagram An enzyme (in Greek en = in and zyme = blend) is a protein, or protein complex, that catalyzes a chemical reaction and also controls the 3D orientation of the catalyzed substrates. ... Structure of Heme b A heme or haem is a prosthetic group that consists of an iron atom contained in the center of a large heterocyclic organic ring called a porphyrin. ... 3-dimensional structure of hemoglobin. ... An apoprotein is a protein without its characteristic prosthetic group. ... Holoprotein is an apoprotein combined with its prosthetic group. ...

Prosthetic groups are also sometimes called coenzyme or cofactors because they are essential to the function of a protein. In enzymes, prosthetic groups are involved in the active site in some way. Further examples of organic prosthetic groups are vitamin derivatives: thiamine (vitamin B₁), thiamine pyrophosphate, pyridoxine (Vitamin B₆), pyridoxal-phosphate. This is another reason why vitamins are so important in our diet. Inorganic prosthetic groups are usually transition metal ions such as iron (in heme groups, for example in cytochrome c oxidase and hemoglobin), zinc (for example in carbonic anhydrase), magnesium (for example in some kinases), and molybdenum (for example in nitrate reductase). A cofactor is any substance that needs to be present in addition to an enzyme to catalyze a certain reaction. ... The active site of an enzyme is the binding site where catalysis occurs. ... For the similarly-spelled nucleic acid, see Thymine Thiamine or thiamin, also known as vitamin B1, is one of the B vitamins. ... Pyridoxal-phosphate (PLP, pyridoxal-5-phosphate) is a cofactor of many enzymatic reactions. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Standard atomic weight 55. ... Structure of Heme b A heme or haem is a prosthetic group that consists of an iron atom contained in the center of a large heterocyclic organic ring called a porphyrin. ... Cytochrome c oxidase The enzyme cytochrome c oxidase (PDB 2OCC, EC 1. ... 3-dimensional structure of hemoglobin. ... General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Standard atomic weight 65. ... Carbonic anhydrase (carbonate dehydratase) is a family of metalloenzymes (enzymes that contain one or more metal atoms as a functional component of the enzyme) that catalyze the rapid interconversion of carbon dioxide and water into carbonic acid, protons, and bicarbonate ions. ... General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white Standard atomic weight 24. ... In biochemistry, a kinase is a type of enzyme that transfers phosphate groups from high-energy donor molecules, such as ATP, to specific target molecules (substrates); the process is termed phosphorylation. ... General Name, Symbol, Number molybdenum, Mo, 42 Chemical series transition metals Group, Period, Block 6, 5, d Appearance gray metallic Standard atomic weight 95. ... Nitrate reducatse are group of enzymes which reduce nitrate to nitrite This article belongs in one or more categories. ...

See also

• Cofactor (biochemistry)