Energy and Matter are essential concepts in all disciplines of science and engineering, often in connection with systems. “The supply of energy and of each needed chemical element restricts a system's operation—for example, without inputs of energy (sunlight) and matter (carbon dioxide and water), a plant cannot grow. Living organisms must take in energy via food, nutrients, or sunlight in order to carry out cellular processes. The transport, synthesis, and breakdown of nutrients and molecules in a cell require the use of energy. All organisms need matter and energy. Sunlight is the major source of energy for organisms on Earth. Plants use the energy from the sun to rearrange the matter in air and water to produce food such as glucose. This process is photosynthesis.The use of energy and matter by living organisms involves chemical cycling from light energy from the sun for the production of chemical energy in food to the decomposition and the returning of chemicals to the cycle. Energy and Matter are essential concepts in all disciplines of science and engineering, often in connection with systems. “The supply of energy and of each needed chemical element restricts a system's operation as, without inputs of energy (sunlight) and matter (carbon dioxide and water), a plant cannot grow. As energy moves through an ecosystem, it changes form, but no new energy is created. Similarly, as matter cycles within an ecosystem, atoms are rearranged into various molecules, but no new matter is created. So, during all ecosystem processes, energy and matter are conserved. The constant exchange of matter and energy between Earth's spheres happens through chemical reactions, radioactive decay, the radiation of energy, and the growth and decay of organisms. In ecosystems, matter and energy are transferred from one form to another. Matter refers to all of the living and nonliving things in that environment. Nutrients and living matter are passed from producers to consumers, then broken down by decomposers. Decomposers break down dead plant and animal matter. Energy flows through the atmosphere and hydrosphere mostly by convection. The continuous cycling of matter and energy through Earth's system makes life on Earth possible. Rain, snow, hail, or sleet fall from clouds, returning water matter to the hydrosphere (oceans, lakes) or geosphere (groundwater, ice sheets). This energy is transferred to the organisms that eat the producers, and then to other organisms that feed on the consumers. Energy moves through an ecosystem when one organism eats another. This movement of energy can be shown as food chains, food webs, and energy pyramids and ecosystem is with a food chain.Organisms also interact with the non-living environment to obtain matter and energy. They do this primarily through processes like photosynthesis and respiration. Matter moves through ecosystems via biogeochemical cycles such as the water, carbon, and nitrogen cycles. Dead producers and consumers and their waste products provide matter and energy to decomposers. Decomposers transform matter back into inorganic forms that can be recycled within the ecosystem. So, the energy that enters an ecosystem as sunlight eventually flows out of the ecosystem in the form of heat. Matter cycles within ecosystems and can be traced from organism to organism. Plants use energy from the Sun to change air and water into matter needed for growth. Animals and decomposers consume matter for their life functions, continuing the cycling of matter.