The Evolution of Photosynthesis and Its Environmental Impact

Starch

“…The glycolytic intermediate fructose-1,6-bisphosphate (FBP) is an activator of AGPase from E. coli, while the enzymes from Agrobacterium tumefaciens and Rhodospirillum rubrum are activated by Fru6P and pyruvate, respectively (Björn and Govindjee 2009;Ballicora et al 2003). Hence, the synthesis of '-glucans needs to be tightly regulated, which is accomplished mainly by controlling the synthesis of ADPglc via AGPase activity.…”

Photosynthetic Microorganisms

“…A majority of photosynthetic organisms assimilate CO 2 via a set of redox reactions, C 3 pathway (Calvin-Benson-Bassham cycle) that occurs without light during photosynthesis (Björn 2008). The cycle was elucidated about 50 years ago as a result of a series of elegant experiments by Calvin, Bassham, and Benson at the University of California, Berkeley, for which a Nobel Prize was awarded in 1961 (Calvin et al 1950).…”

Photosynthesis on exoplanets and exomoons from reflected light

“…With regards to this issue, an important point to note is that many components of the photosynthetic apparatus were probably ported over from chemoautotrophs, with notable examples including: (i) iron-sulfur proteins, (ii) reduced ferredoxins and quinones, and (iii) oxidized electron carriers (e.g., cytochromes and cupredoxins). Hence, it is plausible that (an)oxygenic photosynthesis evolved from chemoautotrophy (Schoepp-Cothenet et al, 2013;Björn and Govindjee, 2015). Moreover, RuBisCO exhibits close similarities to other proteins, such as 2,3-diketo-5-methylthiopentyl-1-phosphate enolase, and may have originated from a protein facilitating sulfur metabolism (Björn and Govindjee, 2015).…”