Fraction of photosynthetic primary productivity carried out by organisms that use water as electron donor

Value 99.9 %
Organism Biosphere
Reference John A. Raven Functional evolution of photochemical energy transformations in oxygen-producing organisms, Functional Plant Biology, 2009, 36, 505–515 p.505 left column top paragraph
Primary Source Raven JA (2009) Contributions of anoxygenic and oxygenic phototrophy and chemolithotrophy to carbon and oxygen fluxes in aquatic environments. Aquatic Microbial Ecology, in press.
Method These organisms that use water as their electron donor use two photochemical reactions in series (Hill and Bendall 1960) to move electrons to NADP+ and then to CO2, and pump H+ across the photosynthetic membrane: the ratio of absorbed photons used : electrons :H+ is 2 : 1 : 3 (Allen 2003, 2004 Falkowski and Raven 2007) BNID 105037. These organisms account for over 99.9% of photosynthetic primary productivity on Earth (Raven 2009).
Entered by Uri M
ID 105038