Why is the six membered cyclic structure of glucose called a pyranose structure? 

The correct answer is ​Pyran is a cyclic organic compound, with one oxygen atom and five carbon atoms in the ring.

Key Points

• The six-membered cyclic structure of glucose is called a pyranose because it resembles the structure of a chemical compound called pyran.
• Pyran is a six-membered ring with five carbon atoms and one oxygen atom.
• In glucose, the six-membered ring forms when the hydroxyl group (-OH) on carbon 5 reacts with the aldehyde group (C=O) on carbon 1, creating a hemiacetal linkage.
• This reaction forms a ring that includes one oxygen atom and five carbon atoms, just like pyran. Hence, the glucose ring structure is termed a pyranose ring.

Important Points

• Glucose, as a carbohydrate, is a fundamental biomolecule involved in various biological processes.
• The pyranose structure of glucose represents its cyclic form, which is crucial in biochemistry for understanding how glucose behaves in cells, participates in metabolism, and forms larger polysaccharides like starch and cellulose.