Anoxygenic photosynthesis

Definition

Anoxygenic photosynthesis is a form of photosynthesis used by certain bacteria that does not produce oxygen as a byproduct. Instead, it utilizes molecules other than water as electron donors.

5 Must Know Facts For Your Next Test

1. Anoxygenic photosynthesis occurs in various groups of phototrophic bacteria including purple sulfur bacteria and green sulfur bacteria.
2. The process uses light energy to extract electrons from molecules like hydrogen sulfide (H2S) instead of water (H2O).
3. Unlike oxygenic photosynthesis, anoxygenic photosynthesis does not release oxygen into the atmosphere.
4. Chlorophyll or bacteriochlorophyll are the pigments involved in capturing light energy.
5. This form of photosynthesis is typically found in anaerobic environments where oxygen is scarce.

Review Questions

• What type of organisms primarily perform anoxygenic photosynthesis?
• What molecule is commonly used as an electron donor in anoxygenic photosynthesis instead of water?
• Why doesn't anoxygenic photosynthesis produce oxygen?

Related terms

Oxygenic Photosynthesis: A type of photosynthesis that produces oxygen by using water as the electron donor.

Phototrophic Bacteria: Bacteria that obtain their energy from light.

Bacteriochlorophyll: A pigment found in phototrophic bacteria used to capture light energy for photosynthesis.