Energy is the ability to do work. In organisms, this work can be physical work, like walking or jumping, or it can be the work used to carry out the chemical processes in their cells. Every biochemical reaction that occurs in an organism’s cells needs energy.
The energy of the sun is first captured by producers organisms that can make their own food. Many producers make their own food through the process of photosynthesis. The “food” the producers make is the sugar, glucose. Producers make food for the rest of the ecosystem.
Phytoplankton, tiny photosynthetic organisms, are the most common producers in the oceans and lakes.
There are also bacteria that use chemical processes to produce food. They get their energy from sources other than the sun, but they are still called producers. This process is known as chemosynthesis, and is common in ecosystems without sunlight, such as certain marine ecosystems.
With just a few exceptions, all life on Earth depends on the sun’s energy for survival.
Producers make food for the rest of the ecosystem through the process of photosynthesis, where the energy of the sun is used to convert carbon dioxide and water into glucose.