Photosynthesis At 1000 ppm CO in measuring air, both the C3 and C4 plants had similar leaf photosynthetic rates around 60 μmol CO·m·s indicating the suppression of photorespiration in C3 plants. There are three main factors affecting photosynthesis and several corollary factors. The three main are: Total photosynthesis is limited by a range of environmental factors. These include the amount of light available, the amount of leaf area a plant has to capture light (shading by other plants is a major limitation of photosynthesis), rate at which carbon dioxide can be supplied to the chloroplasts to support photosynthesis, the availability of
Anoxygenic photosynthesis anew. Molecular hydrogen in the bacterial environment is the usual electron donor. Anoxygenic photosynthesis The pigments used to carry out anaerobic photosynthesis are similar to chlorophyll but differ in molecular detail and peak wavelength of light absorbed. Bacteriochlorophylls "a" through "g" absorb electromagnetic photons maximally in the near-infrared within their natural membrane milieu. This differs from chlorophyll a, the predominant plant and cyanobacteria pigment, which has peak absorption wavelength approximately 100 nanometers shorter (in the red portion of the visible spectrum). Some archaea (e.g. "Halobacterium") capture light energy for metabolic function and are thus phototrophic but none are known to