A Photosynthetic Timeline
1905 F. F. Blackman
-developed the concept of limiting factors, showed that photosynthesis consists of two types of reactions: a rapid light-dependent photochemical process and a slower temperature-dependent biochemical process. These are later termed "light reactions" and "dark reactions," respectively.¹
1941 Cornelis van Niel
-published his work showing that photosynthetic bacteria which used H2S as an electron donor produced elemental sulfur instead of oxygen
- He suggested that the O2 released in plant photosynthesis is derived from H2O rather than CO2.
-analyzed photosynthesis as it occurs in a number of purple bacteria.
-determined that photosynthesis is a redox reaction with H2X as the electron donator (the oxydizable substance)¹
1956 Melvin Calvin
-with his team, they used the carbon 14 tracer and mapped the complete route that carbon travels through a plant during photosynthesis, starting from its absorption as atmospheric carbon dioxide to its conversion into carbohydrates and other organic compounds
- showed that chlorophyll uses radiant energy to split water molecules into hydrogen and oxygen.¹
1954-55 Daniel Arnon
-demonstrated light-dependent ATP formation in chloroplasts.
-demonstrated that isolated chloroplasts are capable of carrying out complete photosynthesis.¹
1984 Hans Deisenhofer, Hartmut Michel & Robert Huber
-determined the three-dimensional structure of a photosynthetic reaction center
- crystallized the photosynthetic reaction center from a purple bacterium and use X-ray diffraction techniques to determine its detailed structure¹
2010 –Researchers at Arizona State University
-created mutations in a single-celled green alga
-Using these mutants, the primary light-triggered electron transfer event in the Photo System I (PSI) reaction center can be initiated independently in each of its parallel branches. At the same time, they showed that PSI has two charge separation devices that effectively work in parallel to increase the overall efficiency of electron transfer²
2000 Xiong J, Fischer WM, Inoue K, Nakahara M, Bauer CE.
Discovered that heliobacteria are the closest to the last common ancestor of all oxygenic photosynthetic lineage and purple bacteria are the earliest emerging photosynthetic lineage. Prior to this it was believed that green nonsulfur bacteria and heliobacteria were the earliest phototrophs(Xiong, Jin 24 Nov. 2012)