Organisms that convert the carbon in organic compounds into carbon dioxide are called decomposers.

Here's why:

* Decomposers are a vital part of the ecosystem. They break down dead organisms and waste products, releasing the nutrients back into the environment.

* Carbon is a key element in organic compounds. When decomposers break down these compounds, they release carbon dioxide as a byproduct.

* Respiration is the process by which decomposers break down organic matter and release carbon dioxide.

Examples of decomposers include bacteria and fungi.