What is the difference between chemosynthesis and photosynthesis?

Photosynthesis and chemosynthesis are both forms of primary production that synthesize organic compounds from carbon dioxide, but they differ fundamentally in their energy sources. Photosynthesis relies on sunlight to drive this biological carbon fixation, whereas chemosynthesis uses chemical energy derived from the oxidation or reduction of inorganic compounds in the absence of sunlight. Both processes serve as vital bases for food chains and global carbon cycling.

What we know

• Photosynthesis uses light as its primary source of energy to synthesize organic compounds from carbon dioxide. [2]
• Chemosynthesis uses the oxidation or reduction of inorganic chemical compounds as its energy source instead of sunlight. [2, 3]
• Both photosynthesis and chemosynthesis act as primary production mechanisms that convert inorganic carbon into organic matter for living organisms. [2, 3]

Where to go next

• what followedHow does biological carbon fixation regulate the global carbon cycle?
• how it workedWhat role do autotrophs play at the base of food chains?
• the bigger pictureWhat is primary production?
• a case in pointHow do plants and algae perform photoautotrophy?
• compared withHow does energy flow through trophic levels in an ecosystem?
• an unexpected connectionHow do sinking zooplankton lipids sequester ocean carbon?While primary production fixes carbon at the surface using light or chemicals, deep ocean carbon transport can rely heavily on the lipids of migrating zooplankton rather than direct particulate organic carbon sinking.

Sources

• [1]primary production (Wikidata Q515905) · CC0 1.0
• [2]Primary production · CC BY-SA 4.0
• [3]Biological carbon fixation · CC BY-SA 4.0
• [4]Energy flow (ecology) · CC BY-SA 4.0
• [5]Lipid pump · CC BY-SA 4.0