Which group of organisms primarily relies on chemical sources of energy?

Chemotrophs are organisms that obtain energy by oxidizing chemical compounds, primarily organic or inorganic molecules. They are distinct from phototrophs, which harness energy from sunlight through photosynthesis. Chemotrophs play a vital role in ecosystems by metabolizing nutrients in their environment to generate ATP, the energy currency of cells.

This group can be divided further into two categories: chemoautotrophs, which can synthesize their organic compounds using carbon dioxide as a carbon source, and chemoheterotrophs, which depend on organic compounds for both energy and carbon. Chemotrophs are found in a variety of environments, including soil, aquatic systems, and even extreme environments like hydrothermal vents.

In comparison, phototrophs rely on light energy, autotrophs can produce their own food from simple substances, and heterotrophs obtain their food from other organisms. These distinctions highlight the unique energy acquisition mechanisms of chemotrophs, making them integral to many biological processes.