Number of chiral carbon atoms present in open chain structure of glucose and fructose respectively.

• Glucose: In the open-chain structure of glucose, there are 4 chiral carbon atoms.
  • The chiral centers are located at carbon atoms C2, C3, C4, and C5 in the glucose molecule.
• Fructose: In the open-chain structure of fructose, there are 3 chiral carbon atoms.
  • The chiral centers are located at carbon atoms C3, C4, and C5 in the fructose molecule.

Summary:

• Glucose: 4 chiral carbons
• Fructose: 3 chiral carbons