Plants require the raw materials of water and carbon dioxide in order to carry out photosynthesis in their chloroplasts. These are reactants in the photosynthesis reaction and the products that form are glucose, oxygen and water. The oxygen gas that forms is a result of the light-dependent reaction that occurs during photosynthesis and during this step, water is split into hydrogen and oxygen. This step is called photolysis and the sun provides the energy for this important step. The oxygen is released out of stomata in the leaves as oxygen gas. Later on, glucose is formed which is chemical energy. If water was scarce, it would be a limiting factor that would affect the survival of plants as well as animals. Less water would mean less photosynthesis for the producers. This in turn would mean a decrease in the production of oxygen which would affect the rate of respiration for aerobic organisms. These include animals, plants, fungi, most protists and some bacteria. During aerobic respiration, a source of chemical energy, like glucose, combines with oxygen and eventually ATP will be produced which is the cell's energy currency. The wastes carbon dioxide and water vapor will be exhaled.