Question

Which form of energy is found in food?

Answer 1

calorie

Answer 2

chemical energy. The body digests and metabolizes the food, which as a chemical reaction releases energy.

( Calorie is a unit of energy, and is not particular to food. )

Answer 3

Seeing how potential energy is that energy associated to the position of an object and the positions of its inner constituents, and how the energy our cells extract from food is mostly due to the relative positions of electrons and nuclei within energy-rich molecules, I guess we could say that the energy found in food is mostly electrostatic potential energy.

Answer 4

The way we usually describe that is chemical energy.

Answer 5

You are right, of course. I was not trying to correct your answer, but rather complement it. There may be readers who do not know exactly what "chemical energy" means and how it relates to other forms of energy.

Let us consider an energy-rich molecule in the context of our living cells, such as adenosine triphosphate (ATP). It has three phosphate groups joined in sequence by two high-energy bonds, and the reason they are high-energy is because, at normal cell conditions, all the available hydroxyl groups (OH) in the phosphates are ionized to O- (they lose the hydrogen's proton while keeping its electron), which causes them to repel each other due to electrostatic interactions. It takes a lot of energy to bring those molecules together despite their electric charge alike, and that energy is locked into the molecule when each phosphate-phosphate bond is formed; that is why those bonds are high-energy.

When a high-energy phosphate bond is broken, the repulsion acts like a compressed spring being released and the energy can be recovered in the resulting motion of the products of the interaction. Our cells couple that motion to all sorts of processes which range from the synthesis of complex molecules to the motion of the cells themselves, and that is why ATP is one of the preferred molecules used to exchange energy within all living cells.

I will attempt to draw it:


It is the negative charge of the ionized oxygens in the phosphates what causes the phosphate bonds to require high energy to form. For simplicity, we can call it "chemical energy" (since the transformations involve chemical reactions) or even "nutritional energy" (since it is stored in nutrients), but it is mostly electrostatic potential energy. And I just hope that helped some one in some way. In any case, happy "new" year.