Question

What is the chief source of the difference in the conversion of energy into useful work of the cell (efficiency) between a cell’s oxidation of glucose (~40%), compared to oxidation of glucose by combustion in air (0%)?

Answer 1

combustion is the burning of a molecule into fundamental samll particles. organic molecules on combustion will yield carbondioxide and water

combustion of glucose to carbondioxide and water will yield energy in biological system. but the cumbustion of glucose in the cell is not taking place with the help of oxygen unlike the outside cell combustion.

in the extracellular combustion, glucose is treated with oxygen and will produce an equivalent energy of 3000kJ per mole of the glucose.

in bilological system the combustion takes place by the cleaving of high energy bonds and formation of high energy molecules called adinosine-tri-phosphosphate.through a preocess called glycolysis. hydrolysis of one mole of ATP will generate 500kJ of energy.

one mole of glucose will generate 36 moles of ATP on complete oxidation. so 36*500= 18000 kJ of energy which is significantly higher than the normal cumbustion of the glucose.