| Nutritional category | Energy source | Carbon source |
|---|---|---|
| Photoautotrophs (some bacteria, some eukaryotes) | Light | Carbon dioxide |
| Photoheterotrophs (some bacteria) | Light | Organic compounds |
| Chemoautotrophs (some bacteria, many prokaryotic archaea) | Inorganic substances | Carbon dioxide |
| Chemoheterotrophs (found in all three domains) | Usually organic compounds; sometimes inorganic substances | Organic compounds |