| Type | Energy Source | Carbon Source | Example |
|---|---|---|---|
| Photoautotroph | Sun | CO2 | Cyanobacteria |
| Photoheterotroph | Sun | Organic compounds | Purple bacteria |
| Chemoautotroph | Chemicals | CO2 | H, S, Fe bacteria |
| Chemoheterotroph | Chemicals | Organic compounds | Most bacteria, fungi, and animals, including humans |