Adenosine triphosphate or ATP is an energy rich compound which undergo hydrolysis in presence of water to generate free energy.
When a molecule is moving against its concentration gradient it requires the input of energy which is generally supplied by the hydrolysis of ATP molecules.
For example Na+K+ATPase uses the energy derived from ATP hydrolysis to transport Na+ inside the cell and K+ outside the cell.
Either, carbon, hydrogen, nitrogen, oxygen, phosphorus, or sulfur. I would go with carbon because of the photosynthesis and cellular respiration<span />
