Phototrophs

Definition

Phototrophs are organisms that obtain energy from light to synthesize organic compounds. They play a crucial role in ecosystems by supporting the food chain and contributing to the oxygen supply through photosynthesis.

5 Must Know Facts For Your Next Test

1. Phototrophs can be found in both Bacteria and Archaea domains.
2. They use pigments like chlorophyll or bacteriochlorophyll to capture light energy.
3. Cyanobacteria are an example of phototrophic bacteria that perform oxygenic photosynthesis.
4. Some phototrophs engage in anoxygenic photosynthesis, using substances other than water as electron donors.
5. Phototrophs contribute significantly to the global carbon cycle by converting inorganic carbon into organic forms.

Review Questions

• What distinguishes phototrophs from chemotrophs?
• How do cyanobacteria contribute to their ecosystems as phototrophs?
• What is the difference between oxygenic and anoxygenic photosynthesis in phototrophs?

Related terms

Chemotrophs: Organisms that obtain energy by oxidizing chemical compounds rather than capturing light.

Cyanobacteria: A group of bacteria that conduct oxygenic photosynthesis, producing oxygen as a byproduct.

Photosynthesis: The process used by phototrophs to convert light energy into chemical energy stored in organic molecules.