Index
We are talking about a monosaccharide whose molecular formula is C₆H₁₂O₆.
Glucose is the most abundant monosaccharide ; It occurs free in fruits, plants, honey, in the blood of animals and is combined in many glycosides, disaccharides and polysaccharides.
Structure and properties
The structure and properties of glucose will be considered in greater detail than those of the other monosaccharides, not only because of their importance, but because much of what can be said about glucose can also be said about the other monosaccharides.
Glucose is an aldohexose, which means it is a six-carbon sugar with a terminal aldehyde group.
Sugars like glucose (C6 H12 O6), with six carbon atoms are known as hexoses and have a sugar unit, making it a monosaccharide. Its name comes from the Greek glykos, which means “sweet.”
In 1888, one of the world’s leading chemists, Emil Fischer, discovered the three sugars, glucose, fructose, and mannose. In 1890, he was the first chemist to synthesize these three sugars from glycerol. He was awarded the 1902 Nobel Prize in Chemistry.
Fischer also confirmed van’t Hoff’s theory, namely the asymmetric carbon atom theory. Level A students will be familiar with the concept of a chiral {asymmetric} carbon atom, often indicated by an asterisk.
Chiral carbons have four different groups attached to them. It is quite remarkable that it also correctly predicted the 3D arrays of glucose with its various chiral carbons.
Chain and ring shape of glucose
Our understanding of sugar chemistry was further increased when the 1937 Nobel Prize in chemistry was awarded to sugar chemist Walter Haworth of the University of Birmingham for his important work on carbohydrates.
When glucose forms the ring structure, it can form two isomers. The isomer where the OH group in C1 is below the plane of the ring is known as alpha-glucose, while the group with the OH group above the ring is known as beta-glucose.
The α and β forms interconvert in a period of a few hours in aqueous solution, however, when glucose polymerizes, the two forms produce polymers with very different properties (starch and cellulose, see below).
Glucose formula
The molecular formula for glucose is C6 H12 O6 or H- (C = O) – (CHOH) 5 -H. Its empirical or simplest formula is CH 2 O, indicating that there are two hydrogen atoms for every carbon and oxygen atom in the molecule.
Glucose is the sugar produced by plants during photosynthesis and circulates in the blood of people and other animals as a source of energy.
Glucose is also known as dextrose, blood sugar, corn sugar, grape sugar, or by its systematic name IUPAC (2 R, 3 S, 4 R, 5 R) -2, 3, 4, 5,6 -pentahydroxyhexanal.
Glucose is an aldehyde (CHO)
Glucose in its chain form can be considered an aldehyde [aldohexose]. It has the structural formula CH 2 OH (CHOH) 4 CHO. It is possible to oxidize the aldehyde group (CHO) to a carboxylic acid group (COOH) using the Tollen reagent.
Tollen’s reagent is essentially ammonia silver nitrate [Ag (NH 3) 2] +. Tollen’s reagent is reduced to elemental silver by the sugar “reducing” glucose, leaving a silver mirror surface on the inside of the test tube. This is known as the silver mirror test.
Tollen reagent preparation: place 2 cm 3 of AgNO 3 (aq) in a test tube. Add 1 drop of dilute NaOH (aq). A brown precipitate of Ag 2 O is observed. Add sufficient dilute NH 3 dropwise (aq) until all of the precipitate simply dissolves, often about 10 drops.
Sugar sources
Table sugar is not glucose, but disaccharide sucrose, formed by the condensation of the monosaccharides glucose and fructose.
Other informations
You can know glucose by another name: blood sugar. Glucose is key to keeping the body’s mechanisms in optimal working order.
When our glucose levels are optimal, it often goes unnoticed. But when they stray from the recommended limits, you will notice the unhealthy effect it has on normal functioning.
Along with fat, glucose is one of the body’s preferred fuel sources in the form of carbohydrates. People get glucose from bread, fruits, vegetables, and dairy products. You need food to create the energy that helps you stay alive.
While glucose is important, as with so many things, it is best in moderation. Unhealthy or out of control glucose levels can have permanent and serious effects.
How does the body process glucose?
Our body processes glucose several times a day, ideally.
When we eat, our body immediately begins to work to process glucose. Enzymes start the breakdown process with the help of the pancreas.
The pancreas, which produces hormones like insulin, is an integral part of how our bodies treat glucose. When we eat, our body clears the pancreas that it needs to release insulin to cope with the rise in blood sugar.
Some people, however, cannot rely on their pancreas to jump out and do the work they are supposed to do.
One of the ways diabetes occurs is when the pancreas does not make insulin the way it should. In this case, people need outside help (insulin injections) to process and regulate glucose in the body.
Another cause of diabetes is insulin resistance, where the liver does not recognize the insulin that is in the body and continues to produce inappropriate amounts of glucose.
The liver is an important organ for sugar control, helping with glucose storage and producing glucose when needed.
If the body does not produce enough insulin, it can result in the release of free fatty acids from fat stores. This can lead to a condition called ketoacidosis.
Ketones, waste products created when the liver breaks down fat, can be toxic in large amounts.
How do you test your glucose?
Testing glucose levels is especially important for people with diabetes. Most people with the condition are used to dealing with blood sugar checks as part of their daily routine.
One of the most common ways to test glucose at home is with a very simple blood test. A finger prick, usually using a small needle called a lancet, produces a drop that is placed on a test strip.
The strip is put into a meter, which measures blood sugar levels. It can usually give you a reading in less than 20 seconds.
