caloric difference between alcohol and carbohydrates

[khugs21]

Hello all, I was wondering how this happens. A gram of a given carbohydrate comes in at 4 calories. However, a gram of alcohol contains 7 calories. Correct me if I am wrong, Im pretty sure I am right , ethyl alcohol is a by product of a fermented sugar (carb). How does this "create" calories? Is there something I am not factoring in? Thanks

 

[mattd2]

Hello all, I was wondering how this happens. A gram of a given carbohydrate comes in at 4 calories. However, a gram of alcohol contains 7 calories. Correct me if I am wrong, Im pretty sure I am right , ethyl alcohol is a by product of a fermented sugar (carb). How does this "create" calories? Is there something I am not factoring in? Thanks

I am not an expert in chem / biology but I would say that the energy density of carb / alc are different. Basically you can't extrate as much energy out of the carbohydrate as you can out of the ethonal

 

[ajdelange]

Carbohydrates have higher energy density than ethanol. If we respire a molecule of glucose we get a lot more energy from it than we do if we ferment it but we still get energy. The unextracted energy is stored in the bonds that hold the ethanol together and can be subsequently extracted by burning the ethanol. On a molar basis your numbers work out to 322 cal/mol for the ethanol and 727 cal/mol for the sugar. But keep in mind that 1 mol of glucose produces 2 mol of ethanol.

 

[Blitzkrieg]

Carbohydrates have higher energy density than ethanol. If we respire a molecule of glucose we get a lot more energy from it than we do if we ferment it but we still get energy. The unextracted energy is stored in the bonds that hold the ethanol together and can be subsequently extracted by burning the ethanol. On a molar basis your numbers work out to 322 cal/mol for the ethanol and 727 cal/mol for the sugar. But keep in mind that 1 mol of glucose produces 2 mol of ethanol.

What he said. Also, it is currently under debate as to how well the human body can use the energy in alcohol. Depending on genetics and how often/much alcohol you consume your body may be more or less equipped to use it as an energy source. Once again it's still under debate.

 

[khugs21]

awesome! thanks all!