Plants store energy in form of starch usually in the roots and/or stem. When there is need for energy such in respiration, starch is converted to glucose which is then used to fuel the process of cellular respiration.
In animals, energy is stored in form of glycogen in the liver and muscle tissues. When there is demand for energy, glycogen is converted back to glucose, which is taken in by the cells and used to fuel cellular respiration
In both plant and animal cells, the purpose of respiration is production of ATP (or adenosine triphosphate), which is the form of energy that cells use.
