In enzymology, a quinoprotein glucose dehydrogenase is an enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

 that catalyzes

Catalysis

Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations....

 the chemical reaction

Chemical reaction

A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity...

D-glucose + ubiquinone D-glucono-1,5-lactone + ubiquinol

Thus, the two substrates

Substrate (biochemistry)

In biochemistry, a substrate is a molecule upon which an enzyme acts. Enzymes catalyze chemical reactions involving the substrate. In the case of a single substrate, the substrate binds with the enzyme active site, and an enzyme-substrate complex is formed. The substrate is transformed into one or...

 of this enzyme are D-glucose and ubiquinone, whereas its two products

Product (chemistry)

Product are formed during chemical reactions as reagents are consumed. Products have lower energy than the reagents and are produced during the reaction according to the second law of thermodynamics. The released energy comes from changes in chemical bonds between atoms in reagent molecules and...

 are D-glucono-1,5-lactone

Glucono delta-lactone

Glucono delta-lactone is a naturally-occurring food additive with the E number E575 used as a sequestrant, an acidifier, or a curing, pickling, or leavening agent. It is a lactone of D-gluconic acid. Pure GDL is a white odorless crystalline powder.GDL is commonly found in honey, fruit juices,...

 and ubiquinol

Ubiquinol

Ubiquinol is an electron-rich form of coenzyme Q10.The natural ubiquinol form of coenzyme Q10 is 2,3-dimethoxy-5-methyl-6-poly prenyl-1,4-benzoquinol, where the polyprenylated side chain is 9-10 units long in mammals...

.

This enzyme belongs to the family of oxidoreductase

Oxidoreductase

In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule to another...

s, specifically those acting on the CH-OH group of donor with a quinone or similar compound as acceptor. The systematic name of this enzyme class is D-glucose:ubiquinone oxidoreductase. Other names in common use include D-glucose:(pyrroloquinoline-quinone) 1-oxidoreductase, glucose dehydrogenase (PQQ-dependent), glucose dehydrogenase (pyrroloquinoline-quinone), and quinoprotein D-glucose dehydrogenase. This enzyme participates in pentose phosphate pathway

Pentose phosphate pathway

The pentose phosphate pathway is a process that generates NADPH and pentoses . There are two distinct phases in the pathway. The first is the oxidative phase, in which NADPH is generated, and the second is the non-oxidative synthesis of 5-carbon sugars...

. It employs one cofactor

Cofactor (biochemistry)

A cofactor is a non-protein chemical compound that is bound to a protein and is required for the protein's biological activity. These proteins are commonly enzymes, and cofactors can be considered "helper molecules" that assist in biochemical transformations....

, PQQ.