This is a type of enzyme that catalyzes (accelerates) reactions where transfers of phosphate groups are made, specifically hexokinase works on the phosphorylation of glucose to form a new compound called "glucose-6-phosphate" (because the phosphorus group is located on carbon number 6 of glucose). In the biochemical reaction that the action of hexokinase is required, it is the process of glycolysis, or degradation of glucose specifically in muscle and other tissues such as brain, red blood cells and among others, the degradation of glucose results in the production of pyruvic acid or pyruvate; the reaction of glycolysis in reverse, results in the formation of glucose from non- carbonic compounds or glucogeneogenesis and occurs at the liver level.
Now, this enzyme was then referred to as hexokinase due to the etymological meaning of the word, "kinase" indicates that the enzyme produces phosphorylation (adds a phosphorous group to the reaction), and "hexo" refers to the reaction being It occurs in hexoses, these are a group of carbohydrates or sugars that are composed of 6 carbons, within this group are glucose, fructose, mannose, among others. One of the essential chemical compounds for the proper functioning of hexokinase is magnesium, this inhibits the negative charges of oxygen or ATP, thus facilitating the combination of the phosphate group with hexose, for this reason it does not work without the presence of magnesium.
Hexokinase has an isoenzyme (they are different but fulfill the same function) this is called glucokinase, the difference between the two is the localization site, hexokinase is found in all cell tissues that require glucose as an energy source, while that glucokinase is only located within hepatocytes, these are cells that make up what is liver tissue(liver). Both fulfill the same function, phosphorylate glucose so that it does not escape from the cell, trapping it to carry out the glycolysis process, another important difference between both enzymes is the compound that inhibits its function, hexokinase stops working if it is possessed glucose-6-phosphate in high concentrations, while glucokinase are inhibited by high amounts of fructose-6-phosphate.
