Molecular mass of RuBisCO (functional octamer)

Value 550 kDa Range: Table - link kDa
Organism Various
Reference Paul G. Falkowski, John A. Raven. Aquatic Photosynthesis. 2007, Princeton University Press pp.190-191 table 5.5
Comments The biochemistry of all terrestrial life depends upon energy from oxidation processes. The end product of metabolic pathways from carbon-based life is carbon dioxide, which is released into the atmosphere. To complete the carbon cycle, that carbon dioxide must be consumed in the food chain. The only enzyme known to break down carbon dioxide is Ribulose-1,5-Bisphosphate carboxylase, or rubisco. Rubisco represents the beginning of the food chain. In some bacteria, rubisco is composed of two identical subunits. In higher photosynthetic organisms, the enzyme is a 16-mer composed of two different subunits, a small subunit and the catalytically active large subunit. Table shows some properties of carboxylases. "All organisms (including human beings) fix CO2 and/or HCO3- in the dark (table 5.5). Dark carbon fixation was noted in the earliest work using 14CO2 to trace the pathways of incorporation of inorganic carbon by Calvin and co-workers (and was largely ignored by them). It is also observed in measurements of macrophyte and phytoplankton primary productivity." See BNID 105007
Entered by Uri M
ID 105006