Can some organisms survive without energy from the sun?

1 Answer
Mar 9, 2017



Yes, there are some organisms we know of that live very deep in the ocean where light does not penetrate. These organisms use energy from chemical reactions and are called chemotrophs. There are a few different types of chemotrophs (see image below).

Chemoautotrophs obtain their energy from chemical reactions and synthesize organic compounds from carbon dioxide. Chemoautotrophs live in places like deep sea vents. They use inorganic sources of energy such as ammonia and hydrogen sulfide.

This is in contrast to chemoheterotrophs which also obtain energy from chemical reactions but are not able to synthesize organic compounds. They use organic sources of energy like lipids and carbohydrates or inorganic sources of energy such as sulfur.

You may want to view this related question on Socratic concerning how chemoautotrophs harvest energy from the environment.