Question

What does '$D$' and $(+)$ signifies in $D-(+)$-glucose?

• A. D represents conformation and (+) represents the laevorotatory nature of molecule
• B. D represents configuration and (+) represents the dextrorotatory nature of molecule
• C. D represents conformation and (+) represents the dextrorotatory nature of molecule
• D. D represents configuration and (+) represents the laevorotatory nature of molecule

Answer 1

Answer: (B)

Glucose is correctly named as $D(+)$-glucose. ' $D$ ' before the name of glucose represents the configuration whereas ' $(+)$ ' represents dextrorotatory nature of the molecule. It may be remembered that ' $D$ ' and ' $L$ ' have no relation with an optical activity of the compound.