coenzyme and ribozyme

Conenzyme and ribozyme Coenzyme: Introduction: An organic  cofactor or prosthetic group (nonprotein portion of the enzyme) whose presence is required for the activity of many enzymes. The prosthetic groups attached to the protein of the enzyme (the apoenzyme) may be regarded as dissociable portions of conjugated proteins. Neither the apoenzyme nor the coenzyme moieties can function singly. In general, the coenzymes function as acceptors of electrons or functional groupings, such as the carboxyl groups in α-keto acids, which are removed from the substrate. Definition: A nonproteinaceous organic substance that usually contains a vitamin or mineral and combines with a specific protein, the apoenzyme, to form an active enzyme system. Or coenzyme: nonprotein organic molecule that temporarily joins with enzyme during reaction, serves as a carrier molecule, is not consumed in reaction, and can be reused until degraded; cofactor.  Or An organic, non-protein cofactor which is needed for the normal functioning of an enzyme. Many vitamins function as coenzymes. Example: Well-known coenzymes include the pyridine nucleotides, nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP); thiamine pyrophosphate (TPP); flavin mononucleotide (FMN) and flavinadenine dinucleotide (FAD); iron protoporphyrin (hemin); uridine diphosphate (UDP) and UDP-glucose; and adenosine triphosphate(ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP).  Explanation: Coenzyme  (kō-ĕn'zīm), any one of a group of relatively small organic molecules required for the catalytic function of certain enzymes. A coenzyme may either be attached by covalent bonds to a particular enzyme or exist freely in solution, but in either case it participates intimately in the chemical reactions catalyzed by the enzyme. Often a coenzyme is structurally altered in the course of these reactions, but it is always restored to its original form in subsequent reactions catalyzed by other enzyme systems. Importance: Coenzymes are essential organic compounds that attach to enzymes to help them catalyze reactions. An enzyme has an active site where it catalyzes the reaction of a substrate, but a coenzyme binds to other areas of the enzyme, changing its shape and allowing the active site to better fit the substrate. Many of the coenzymes in our diet are essential vitamins we need to carry out reactions for cell function. The function of the coenzyme is to bring an added element to the reaction such as an electron or functional group Ribozymes: Definition: A ribozyme (from ribonucleic acid enzyme, also called RNA enzyme or catalytic RNA) is an RNA molecule possessing a well defined tertiary structure that enables it to catalyze a chemical reaction Explanation: Many natural ribozymes catalyze either the hydrolysis of one of their own phosphodiester bonds (self-cleaving ribozymes), or the hydrolysis of bonds in other RNAs, but they have also been found to catalyze the aminotransferase activity of the ribosome. Example: Common example includes Peptidyl transferase 23S rRNA Hairpin ribozyme Hammerhead ribozyme HDV ribozyme Mammalian CPEB3 ribozyme VS ribozyme CoTC ribozyme Applications: A type of synthetic ribozyme directed against HIV RNA called gene shears has been developed and has entered clinical testing for HIV infection