Quantum mechanics explains efficiency of photosynthesis
Photosynthetic Efficiencies of LEDs: Results of Short …
Quantum mechanics explains efficiency of photosynthesis
We describe on the successful coupling of photochemical NADH regeneration with redox enzymatic synthesis by using proflavine as a light-harvesting molecule. Proflavine, a promising photosensitizer, exhibited a high capacity to drive the reduction of NAD into NADH in the presence of a Rh-based electron mediator, and the photoregenerated NADH was enzymatically active to be oxidized by NADH-dependent L-glutamate dehydrogenase for the synthesis of L-glutamate. Both the wavelength and intensity of incident light were found to significantly affect the efficiency of photochemical NADH regeneration. In contrast to proflavine, flavin derivatives, such as FAD, FMN, lumichrome, and riboflavin, accelerated solely the rate of NADH oxidation, not that of NAD reduction. Our results indicate that proflavine has the potential to become an efficient light harvesting component in biocatalytic photosynthesis driven by solar energy.
People are usually surprised to hear that grass is a relatively recent plant innovation. and only became common in the late Cretaceous, along with flowering plants. With grass, some , and grazers have been plentiful Cenozoic herbivores. According to , carbon dioxide levels have been falling nearly continuously for the past 150-100 million years. Not only has that decline progressively cooled Earth to the point where we live in an ice age today, but is currently considered the key reason why complex life may become extinct on Earth in several hundred million years. In the Oligocene, between 32 mya and 25 mya some plants developed a during photosynthesis known as . It allowed plants to adapt to reduced atmospheric carbon dioxide levels. C4 plants became in the Miocene, and grasses are today’s most common C4 plants and . The rest of Earth’s photosynthesizers use or , which is a water-conserving process used in arid biomes.
RQE - Relative Quantum Efficiency | AcronymFinder
The majority of light-gathering macromolecules are composed of chromophores (responsible for the colour of molecules) attached to proteins, which carry out the first step of photosynthesis, capturing sunlight and transferring the associated energy highly efficiently. Previous experiments suggest that energy is transferred in a wave-like manner, exploiting quantum phenomena, but crucially, a non-classical explanation could not be conclusively proved as the phenomena identified could equally be described using classical physics.
“Energy transfer in light-harvesting macromolecules is assisted by specific vibrational motions of the chromophores,” said Alexandra Olaya-Castro (UCL Physics & Astronomy), supervisor and co-author of the research. “We found that the properties of some of the chromophore vibrations that assist energy transfer during photosynthesis can never be described with classical laws, and moreover, this non-classical behaviour enhances the efficiency of the energy transfer.”
Efficiency of Photosynthesis ..
AB - As the partial pressure of CO2 (pCO2) in the atmosphere rises, photorespiratory loss of carbon in C3 photosynthesis will diminish and the net efficiency of light-limited photosynthetic carbon uptake should rise. We tested this expectation for Indiana strawberry (Duchesnea indica) growing on a Maryland forest floor. Open-top chambers were used to elevate the pCO2 of a forest floor habitat to 67 Pa and were paired with control chambers providing an ambient pCO2 of 38 Pa. After 3.5 years, D. indica leaves grown and measured in the elevated pCO2 showed a significantly greater maximum quantum efficiency of net photosynthesis (by 22%) and a lower light compensation point (by 42%) than leaves grown and measured in the control chambers. The quantum efficiency to minimize photorespiration, measured in 1% O2, was the same for controls and plants grown at elevated pCO2. This showed that the maximum efficiency of light-energy transduction into assimilated carbon was not altered by acclimation and that the increase in light-limited photosynthesis at elevated pCO2 was simply a function of the decrease in photorespiration. Acclimation did decrease the ribulose-1,5-bisphosphate carboxylase/oxygenase and light-harvesting chlorophyll protein content of the leaf by more than 30%. These changes were associated with a decreased capacity for light-saturated, but not light-limited, photosynthesis. Even so, leaves of D. indica grown and measured at elevated pCO2 showed greater light-saturated photosynthetic rates than leaves grown and measured at the current atmospheric pCO2. In situ measurements under natural forest floor lighting showed large increases in leaf photosynthesis at elevated pCO2, relative to controls, in both summer and fall. The increase in efficiency of light-limited photosynthesis with elevated pCO2 allowed positive net photosynthetic carbon uptake on days and at locations on the forest floor that light fluxes were insufficient for positive net photosynthesis in the current atmospheric pCO2.
In photosystem II (PSII) the probability that energy absorbed by core antenna chlorophyll (Chl) is transferred to the reaction center (RC) is extremely high. Although close proximity between antenna Chl ensures a high transfer efficiency, relative pigment orientation can fractionally modify it. This level of refinement has often been assumed to be superfluous as so many subsequent processes limit the overall efficiency of photosynthesis. Nevertheless, did natural selection act on the most efficient step of energy conversion in PSII by optimizing the orientation of antenna Chl? Our Monte Carlo simulations sampled the orientation space of Chls in kinetic models for excitation energy transfer based on the X-ray structures of PSII from Thermosynechococcus vulcanus and Synechocystis elongatus. Our results revealed that the orientations of key antenna Chls are optimized to maximize photosynthesis while the orientations of the two peripheral RC Chls (Chl Z) are not.
phase of photosynthesis and the efficiency of the ..
Relative photosynthetic efficiency following lead application ..
Brassinosteroids Alleviate Heat-Induced Inhibition of Photosynthesis by Increasing Carboxylation Efficiency and ..
Quantum Mechanics Explains Efficiency of Photosynthesis
Relative Quantum Efficiency ..
Quantum Mechanics Explains Efficiency of Photosynthesis ..
evidence of quantum effects in photosynthesis
QUANTUM MECHANICS EXPLAINS EFFICIENCY OF PHOTOSYNTHESIS ..
Peptide self-assembly is an attractive route to the synthesis of intricate organic nanostructures that possess remarkable structural variety and biocompatibility. Recent studies on peptide-based, self-assembled materials have been expanding beyond the construction of high-order architectures; they are now reporting new functional materials that have applications in the emerging fields, such as artificial photosynthesis and rechargeable batteries. Nevertheless, there have been rather scarce reviews particularly concentrating on such versatile, emerging applications. Herein we selectively review recent advances in the synthesis of self-assembled peptide nanomaterials (e.g., cross beta-sheet-based amyloid nanostructures, peptide amphiphiles, etc.) and describe their new applications in diverse, interdisciplinary fields ranging from optics, energy storage/conversion to healthcare. We highlight the applications of peptide-based self-assembled materials in unconventional fields, such as photoluminescent peptide nanostructures, artificial photosynthetic peptide nanomaterials, and lithium-ion battery components. We also discuss relation of such functional materials to the rapidly progressing biomedical applications of peptide self-assembly, which include biosensors/chips and regenerative medicine. The combination of strategies shown in respective applications would further promote the discovery of novel, functional small materials.
of quantum effects in photosynthesis ..
Cellulose, a main component of green plants, is the most abundant organic chemical on Earth, produced 1011 tons per year in the biosphere. The polysaccharide consists of D-glucose units linked by beta-1,4-glycosidic bonds and has been widely utilized in diverse engineering fields because of its biocompatibility, abundance, and high chemical stability. In this work, we have demonstrated the utility of carboxymethyl cellulose (CMC) fibers as a sacrificial template to produce binary and tertiary metal oxides fibers. The electrostatic interaction between metal ions and the carboxyl groups in CMC fibers induced a hierarchical structure of metal oxides. The morphologies of synthesized metal oxides (e.g., CeO2, ZnO, and CaMn2O4) could be controlled according to synthetic conditions, such as metal precursor concentration, calcination temperature, and the amount of CMC fibers. Thus-synthesized CMC-templated metal oxide fibers exhibited enhanced performances for photocatalytic, photochemical, and electrocatalytic reactions. The CeO2 fibers showed much higher photocatalytic activity than CeO2 nanoparticles due to superior ability to generate reactive oxygen species which can degrade organic pollutants. We also demonstrated that hierarchical ZnO fibers hybridized with g-C3N4 could provide directional charge transfer pathway and showed their utility for biocatalyzed artificial photosynthesis through visible light-driven chemical NADH regeneration coupled with redox enzymatic reaction. The electrochemical properties of CaMn2O4 fibers enabled bi-functional reactions of oxygen reduction and evolution reactions. We expect that the economical and environmentally friend approach could be extended to green synthesis of hierarchically structured materials of other metal oxides.
secret to the remarkable efficiency of photosynthesis
We identified 519 genes (53.7%) with no homologues in either the National Center for Biotechnology Information (NCBI) databases or other heterokont genomes (e-value > 1e-10). An additional 122 genes (12.6%) code for conserved genes with unknown function. Of these 122 conserved genes, 23 (18.9%) are conserved only within the heterokont lineage. The remaining 325 genes (33.6%) were divided into 12 groups according to their putative functions in amino acid metabolism, DNA replication and protein synthesis, protein turnover, carbohydrate metabolism, photosynthesis-related processes, fatty acid metabolism, transporters, vesicular trafficking and cytoskeleton, classical stress response pathways, autophagy, signaling, and other processes. The following section gives a brief overview of the different groups of genes identified among the most significantly regulated genes.
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