* Photosynthesis: Plants and other photosynthetic organisms capture sunlight and use it to convert carbon dioxide and water into glucose (sugar) and oxygen. This process stores energy from the sun in chemical bonds of the glucose molecule.
* Cellular Respiration: All living organisms, including plants and animals, use glucose as fuel. They break down glucose through cellular respiration, releasing the stored energy in the form of ATP (adenosine triphosphate). ATP is the primary energy currency of cells, powering all their essential functions.
So, the energy flow looks like this:
1. Sun provides energy.
2. Photosynthesis in plants and other organisms captures sunlight and converts it to chemical energy in glucose.
3. Cellular respiration in all living organisms breaks down glucose, releasing energy in the form of ATP.
4. ATP powers all life processes, such as growth, movement, and reproduction.
Other Sources of Energy:
* Chemosynthesis: Some organisms, particularly those found in deep-sea vents, obtain energy from the oxidation of inorganic compounds like hydrogen sulfide, instead of sunlight.
* Geothermal Energy: Organisms living in extreme environments, like hot springs, can utilize geothermal energy.
Ultimately, all life on Earth is directly or indirectly dependent on the sun as its primary energy source.
