Glucose C6H12O6, also known as D-glucose or dextrose is a simple monosaccharide found in plants and necessary for our survival. It is absorbed directly into the bloodstream during digestion. Cells use it as a secondary source of energy and a metabolic intermediate. Glucose is one of the main products of photosynthesis and it is a main fuel for cellular respiration. Glucose exists in several different molecular structures, but all of these structures can be divided into two families of mirror-images (stereoisomers). Only one set of these isomers exists in nature, those derived from the "particular chiral form" of glucose, denoted D-glucose.
Glucose is very important in our own diets and it is especially important for diabetic individuals to be aware of their intake of it. For instance if someone is having a diabetic emergency and it hypoglycemic, the best thing to do is to have them ingest glucose tablets or gels. Having something like a sugary drink or candy will not work as fast because it is an alternate form of sugar and must first be broken down into glucose before it can be properly used in the blood stream. Too much glucose is also a issue especially when your bodies insulin response is abnormal.
The chemical D-glucose is sometimes referred to as dextrose, a historical name that derives from dextrorotatory glucose because a solution of D-glucose in water rotates the plane of polarized light to the right (dextro). However, the D- in D-glucose refers to a chiral chemical similarity property in sugars, not the property of rotating light (for example, D-fructose rotates light to the left). For this reason, the D- and L- designations in sugars do not perfectly predict optical rotation, and do not refer to this property.
Glucose or D - Glucose has a total of four chiral centers with the following stereochemistry: