How much usable energy. is available during oxidative combustion of 1 gm molecule of glucose in the body?

Answer: Option A

686000 cal usable energy is available during oxidative combustion of 1 gm molecule of glucose in the body.
Combustion involves a complete oxidation reaction where biomass reacts with excess oxygen at high temperatures (700 - 1400°C) to generate heat in the form of steam and other gaseous by-products such as carbon dioxide (CO₂) and water (H₂O).
Complete oxidation of one molecule of glucose results in the production of the equivalent of 38 molecules of ATP. 1 gram of glucose molecule yields 686 kcal, which is equivalent to 686000 calories of energy.