heat of combustion is the heat released by the complete combustion of one mole of a substance?

Question

true or false

Answer 1

True

Answer 2

That is true, for gasoline in a car , but the Heat of Combustion means much more when used in Biology

In biology It means the "energy" released by complete oxidation of a mole of a substance.
Simply because, a cell might take a mole of fat, oxidize it , but capture the energy in a high energy ATP bond,
Although it was combusting the fat, the cell used enzymes to capture chemical energy instead of Heat energy.

The amount of energy released is equal to the amount of energy in heat combustion.

But the form of the energy varies.
The Heat of combustion is an easy way to Quantify the amount of energy released by oxidation.