What is the Difference Between Glucose Galactose and Mannose?

Glucose, galactose, and mannose are all monosaccharides, which are simple sugars that cannot be hydrolyzed into smaller sugars. They have different chemical structures and properties:

1. Glucose:

• Six-carbon sugar.
• Naturally produced through photosynthesis in plants.
• Serves as an energy source for cells.

1. Galactose:

• C4-epimer of glucose.
• Produced through the hydrolysis of lactose, catalyzed by the lactase enzyme.
• Found in milk sugar (lactose).

1. Mannose:

• C2-epimer of glucose.
• Differs from glucose at the second carbon chiral center (C2 position).
• Present in some glycoproteins and glycolipids.

In a color reaction test, glucose produces a lilac color, mannose produces a brown color, and galactose produces a red color. These differences in chemical structure and properties lead to distinct biochemical features for each sugar.

Comparative Table: Glucose Galactose vs Mannose

Here is a table comparing the differences between glucose, galactose, and mannose:

Both glucose and galactose have the same chemical formula (C6H12O6), but they differ in their stereochemistry, with galactose being the C4 epimer of glucose. All three molecules are monosaccharides, which are simple sugars that cannot be further hydrolyzed to simpler compounds. Glucose is the primary source of energy for animals and is produced in plants and algae through photosynthesis. Galactose, on the other hand, is found in milk sugars and forms lactose when combined with glucose. Mannose is another monosaccharide but has no specific function or source mentioned in the provided search results.