Explain how carbon-based molecules provide energy to cells.

Molecules are groups of bonded atoms. Energy is required to form these atoms, and since, according to the First Law of Thermodynamics, energy is never created or destroyed, energy is therefore released when these bonds are broken. 

Now that we know this, we can infer that carbon-based molecules provide energy to cells when the bonds of the atoms that form the molecule are broken, and release energy.

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