Galactose is a sugar that is found in milk. In other words, we can say that it is milk sugar. However, it is made up of two sugars, gal and glucose. Furthermore, it is 65% as sweet as sucrose. The milk consists of acid known as lactic acid and has lactose present in it. Moreover, a galactor molecule linked with glucose molecule forms a lactose molecule.

Galactose and Glucose

Galactose

It is abbreviated as Gal and is a monosaccharide sugar that is sweeter than glucose. Though, the main dietary source is glucose.

DGalactose is a monosaccharide sugar that serves as an energy source and glycosylation component. It is a C-4 epimer of glucose and often used as a source of carbon in culture media. Galactose is a component of the disaccharide lactose and released upon hydrolysis by β-galactosidase enzymes.

Glucose

It is a monosaccharide and is a simple sugar. The naturally occurring glucose is known as D-Glucose, but L-Glucose does not occur naturally. However, it does not has any colour and gets dissolved in water very easily.

It is a subcategory of carbohydrates and the most abundant monosaccharide. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using energy from sunlight, where it is used to make cellulose in cell walls.

Galactose Structure

The chemical formula of galactose, as well as glucose, is the same, i.e: C6H12O6.

Glucose and Galactose

Similarly, both of them are two different types of carbohydrates. The formula for both is the same but the main difference is the position of each hydroxyl group in the carbon.

Although the main difference is that glucose is a simple sugar and tastes sweet. Gal is also a simple sugar but is less sweet than glucose.

The melting point of gal is 167oC which is much higher than glucose as the melting point of glucose is about 145-150oC.

The –OH group of the 4th carbon of D-Gal is directed towards the left side whereas, in D-Glucose, it is directed towards the right side.

Finally, both of them are composed of C, H and O atoms but glucose is sweeter than a gal.

Beta d Glucose

BetaDglucose is d-Glucopyranose with the beta configuration at the anomeric centre. It has a role as an epitope and a mouse metabolite. It is an enantiomer of beta-L-glucoseBetaD-Glucopyranose is the beta isoform of D-glucopyranose, a synthetic simple monosaccharide as an energy source.

Conclusion

  1. Glucose is a monosaccharide and is a simple sugar.
  2. A galactor molecule linked with glucose molecule forms a lactose molecule.
  3. The main dietary source of gal is glucose.
  4. Glucose does not has any colour and gets dissolved in water very easily.
  5. Gal and Glucose are two different types of carbohydrates.

Frequently Asked Questions

How is galactose different from glucose?

The difference is only in the position of one hydroxyl group. This makes galactose different from glucose. This gives gal different chemical and biochemical properties to glucose.

What is galactose made of?

Galactose is a sugar found in milk. It is a disaccharide and is made up of two sugars, gal and glucose.

What is a galactose free diet?

Most of the food containing protein are galactose free such as chicken, poultry and eggs. In galactose free diet, the calcium level becomes very low. It is suggested to add calcium supplements.