When the organism is resting and energy is not immediately needed, the reverse reaction takes place and the phosphate group is reattached to the molecule using energy obtained from food or sunlight.

The ticking of a clock has a randomness of zero; radioactive decay and other simple Poisson processes ... pari pasu with the arrival of each fresh ATP molecule. Under conditions of high load ...

ATP (adenosine triphosphate) is the energy-carrying molecule used in cells because it can release energy very quickly. Energy is released from ATP when the end phosphate is removed. Once ATP has ...

If oxygen is available to the cell then the pyruvate molecules can be further broken down in stage two to release more energy and produce a greater quantity of ATP. A pyruvate molecule enters the ...