Question

Why glucose have cyclic structure and not linear structure?

Answer 1

Glucose is one of the many carbohydrate molecules found in nature. It is named after the ratio of hydrogen to oxygen, which comes out as 2:1, the same as water. The formula of glucose is C6H12O6, and it exists primarily in two forms, the open chain and ring forms. The ring form is formed by reacting the free aldehyde end of open chain glucose with one of the hydroxyl groups attached to other carbon atoms of the chain. As open chain glucose has an aldehyde, it is termed an aldose.

We start off by examining the structure of open chain glucose. This orientation is easily recognized as the Fischer projection of D-glucose, with the hydroxyl groups arranged in a particular way.