Natural glucose, either free or combined, is a D-configuration, in aqueous solutions mainly in the presence of the pyrrole-like oxygen ring, the equilibrium mixture of both α and β configurations.
At room temperature, the hydrate (containing 1 water molecules) can α-d-glucose from supersaturated aqueous solution, and the melting point is 80 ℃, while the crystals separated from 50~115℃ are anhydrous α-d-glucose, melting point 146 ℃. The stable form of ℃ above 115 is β-d-glucose and the melting point is 148~150℃. The glucose in the form of furan ring exists only in a few natural compounds in a combination state.
D-Glucose has the property of general aldehyde sugar: under the action of oxidant, the formation of dextrose acid, glucose, acid or glucosamine, and the formation of Sls alcohol under the action of reducing agent; Under the action of weak alkali, glucose can be transformed into ── fructose and mannose ──, which are similar to two other six-carbohydrate structures. Glucose can also be combined with phenylhydrazine to produce glucose osazone, which is different from other sugars osazone in crystalline shape and melting point, which can be used as a means to identify glucose.
Most organisms have the ability to decompose D-glucose to gain energy by enzymatic systems. In living cells, such as mammalian muscle cells or single-cell yeast cells, glucose has undergone anaerobic glycolysis pathway, oxygen-requiring tri-carboxylic acid cycle and biological oxidation process to generate carbon dioxide and water, releasing more energy, in the form of ATP (adenosine triphosphate) stored in order to grow, sports and other life activities need. In the absence of oxygen, glucose is only decomposed to produce lactic acid or ethanol, releasing much less energy, and wine-making is the process of anaerobic decomposition. Industrially, the glucose produced by acid or enzymatic hydrolysis of starch can be used as a raw material for food, wine making and pharmacy.