A dehydrogenase is an enzyme belonging to the group of oxidoreductases that oxidizes a substrate by reducing an electron acceptor, usually NAD+/NADP+ [1] or a flavin coenzyme such as FAD or FMN. Like all catalysts, they catalyse reverse as well as forward reactions, and in some cases this has physiological significance: for example, alcohol dehydrogenase catalyses the oxidation of ethanol to acetaldehyde in animals, but in yeast it catalyses the production of ethanol from acetaldehyde. Dehydrogenases oxidize a substrate by transferring hydrogen to an electron acceptor, common electron acceptors being NAD+ or FAD. This would be considered an oxidation of the substrate, in which the substrate either loses hydrogen atoms or gains an oxygen atom. The name dehydrogenase is based on the idea that it facilitates the removal of hydrogen and is an enzyme (-ase). Dehydrogenase reactions come most commonly in two forms: the transfer of a hydride and release of a proton, and the transfer of two hydrogens. Aldehydes are the natural by-product of many physiological processes, as well as being the consequence of many industrial processes, put out into the environment in the form of smog and motor vehicle exhaust. Build-up of aldehydes in the brain and pericardium can be detrimental to a person's health, as they can form adducts with important molecules and cause their inactivation. Deactivation of aldehyde dehydrogenases has been shown to be instrumental in the mechanisms of many cancers. ALDHs function in cell differentiation, proliferation, oxidation, and drug resistance. These enzymes are only one example of the many different types of dehydrogenases in the human body; their wide array of functions, and the impact that their deactivation or mutations has upon crucial cell processes underscores the importance of all dehydrogenases in maintaining body homeostasis. Dehydrogenases are enzymes that catalyze reduction reactions through the transfer of hydrogen ions (protons) from the substrate to an acceptor or co-enzyme. Co-enzymes are small organic molecules involved in enzyme catalysis, such as nicotinamide adenine dinucleotide (NAD+ or NADH), nicotinamide adenine dinucleotide phosphate (NADP+ or NADPH), flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN). Glucose-6-phosphate dehydrogenase deficiency is a genetic disorder that affects red blood cells, which carry oxygen from the lungs to tissues throughout the body. In affected individuals, a defect in an enzyme called glucose-6-phosphate dehydrogenase causes red blood cells to break down prematurely. This destruction of red blood cells is called hemolysis. This test measures the level of the different lactate dehydrogenase (LDH) isoenzymes in the blood. LDH, also known as lactic acid dehydrogenase, is a type of protein, known as an enzyme. LDH plays an important role in making your body's energy. It is found in almost all the body's tissues. When tissues are damaged or diseased, they release LDH isoenzymes into the bloodstream. The type of LDH isoenzyme released depends on which tissues are damaged. This test can help your provider find out the location and cause of your tissue damage. A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

Regards,

Deber Peter,

Managing Editor,

Journal of Biological & Chemical chronicles