photosynthesis

Edge evidence

• photosynthesis enables photosynthesis RO:0002327

  Reaction-center photochemistry underlies the photosynthetic trait.

  • DOI:10.1016/j.tim.2006.09.001 Bryant & Frigaard treat reaction-center photosynthesis as encompassing both oxygenic and anoxygenic forms.
• photosynthesis contributes to carbon fixation RO:0002326

  Photosynthetic electron flow powers autotrophic CO2 fixation.

  • DOI:10.1146/annurev-earth-060313-054810 Fischer et al. frame reaction-center photosynthesis as the chlorophyll-based, CO2-fixing branch of phototrophy.
• light energy enables light harvesting / excitation transfer RO:0002327

  Light energy drives pigment absorption and excitation transfer to reaction-center antennae.

  • DOI:10.1111/1751-7915.14519 Chlorophyll/antenna pigments absorb and transfer light energy to the photosystems (light harvesting).
• light harvesting / excitation transfer initiates reaction-center charge separation

  Transferred excitation energy drives primary charge separation at the reaction-center special pair.

  • DOI:10.3390/biom14030311 Light-driven charge separation in reaction-center photosystems initiates downstream electron flow (generic to Type I/II RCs).
• reaction-center charge separation powers photosynthetic electron transport

  Reaction-center charge separation drives photosynthetic electron transport (linear or cyclic).

  • DOI:10.3390/biom14030311 Light-driven charge separation powers electron transfer pathways; generalization for reaction-center photosystems.
• photosynthetic electron transport generates transmembrane electrochemical proton gradient biolink:produces

  Photosynthetic electron transport establishes a transmembrane electrochemical proton gradient.

  • DOI:10.3390/biom14030311 Electron transfer creates a transmembrane electrochemical proton gradient (energy-conservation edge).
• transmembrane electrochemical proton gradient drives ATP synthesis

  The proton motive force is used to drive chemiosmotic ATP synthesis.

  • DOI:10.3390/biom14030311 The electrochemical proton gradient drives ATP synthesis; canonical bioenergetic edge.
• photosynthesis produces reducing power (NAD(P)H) METPO:2000202

  Light-dependent reactions generate ATP and NAD(P)H reducing power.

  • DOI:10.5287/ora-8jgz2nrvd Light-dependent reactions generate ATP and NAD(P)H; broad linkage across chlorophyll-based photosynthetic systems.
• reducing power (NAD(P)H) used in carbon fixation

  NADPH reducing power supplies electrons for autotrophic CO2 fixation.

  • DOI:10.1111/1751-7915.14519 NADPH from the light reactions is used in biosynthesis, including carbon fixation.