1 Without its atmosphere, Earth would be a very different planet. 2  Gases in the atmosphere allow plants to photosynthesize and animals and plants to engage in respiration. 3  Water vapor, which is an atmospheric gas, is an essential part of the water cycle. 4  All weather takes place in the atmosphere.
Energy transformation can also be explained in terms of potential energy, the stored energy of a system, which can be converted into kinetic energy, the energy of movement. For example, a roller coaster sitting at the top of a hill is said to have potential energy.
The Transformation of Energy. The transformations of energy in an ecosystem begin first with the input of energy from the sun. Energy from the sun is captured by the process of photosynthesis. Carbon dioxide is combined with hydrogen (derived from the splitting of water molecules) to produce carbohydrates (CHO). Energy is stored in the high energy bonds of adenosine triphosphate, or ATP (see lecture on photosynthesis).