Photosynthesis can be described by the simplified chemical reaction where C6H12O6 is glucose (which is subsequently transformed into other sugars, starches, cellulose, lignin, and so forth).
For actual sunlight, where only 45% of the light is in the photosynthetically active wavelength range, the theoretical maximum efficiency of solar energy conversion is approximately 11%.
In actuality, however, plants do not absorb all incoming sunlight (due to reflection, respiration requirements of photosynthesis and the need for optimal solar radiation levels) and do not convert all harvested energy into biomass, which results in a maximum overall photosynthetic efficiency of 3 to 6% of total solar radiation.
[6] This dramatically reduces average achieved photosynthetic efficiency in fields compared to peak laboratory results.
[7] Some pigments such as B-phycoerythrin that are mostly found in red algae and cyanobacteria has much higher light-harvesting efficiency compared to that of other plants.
Ethanol fuel in Brazil has a calculation that results in: "Per hectare per year, the biomass produced corresponds to 0.27 TJ.
C4 plants use a modified Calvin cycle in which they separate Ribulose-1,5-bisphosphate carboxylase oxygenase (RuBisCO) from atmospheric oxygen, fixing carbon in their mesophyll cells and using oxaloacetate and malate to ferry the fixed carbon to RuBisCO and the rest of the Calvin cycle enzymes isolated in the bundle-sheath cells.
In Crassulacean acid metabolism (CAM), time isolates functioning RuBisCO (and the other Calvin cycle enzymes) from high oxygen concentrations produced by photosynthesis, in that O2 is evolved during the day, and allowed to dissipate then, while at night atmospheric CO2 is taken up and stored as malic or other acids.
During the day, CAM plants close stomata and use stored acids as carbon sources for sugar, etc.
Around 25% of the time RuBisCO incorrectly collects oxygen molecules instead of CO2, creating CO2 and ammonia that disrupt the photosynthesis process.
Plants remove these byproducts via photorespiration, requiring energy and nutrients that would otherwise increase photosynthetic output.
The study employed synthetic biology to construct new metabolic pathways and assessed their efficiency with and without transporter RNAi.
[15] Far-red In efforts to increase photosynthetic efficiency, researchers have proposed extending the spectrum of light that is available for photosynthesis.
One approach involves incorporating pigments like chlorophyll d and f, which are capable of absorbing far-red light, into the photosynthetic machinery of higher plants.