Quantum biology: Algae evolved to switch quantum coherence on and off

Quantum biology: Algae evolved to switch quantum coherence on and off: "Most cryptophytes have a light-harvesting system where quantum coherence is present. But we have found a class of cryptophytes where it is switched off because of a genetic mutation that alters the shape of a light-harvesting protein.
"This is a very exciting find. It means we will be able to uncover the role of quantum coherence in photosynthesis by comparing organisms with the two different types of proteins."

Team models photosynthesis and finds room for improvement

Team models photosynthesis and finds room for improvement: "We've modeled the whole system, and added all the components in a cyanobacterial system one at a time to our computer simulation to see if they give us an advantage."

The team found that some of the carboxysome genes hindered, while others greatly enhanced photosynthetic efficiency in crop plants such as soybean, rice and cassava...

"And if we put in about eight components of the carboxysome system, the model says that we could get a 60 percent increase in photosynthesis," he said.

Mathematical study of photosynthesis clears the path to developing new super-crops

Mathematical study of photosynthesis clears the path to developing new super-crops: Around three per cent of all plants use an advanced form of photosynthesis, which allows them to capture more carbon dioxide, use less water, and grow more rapidly. Overall this makes them over 50% more efficient than plants that use the less efficient form.

What We Can Learn From the Quantum Calculations of Birds and Bacteria - Wired Science

What We Can Learn From the Quantum Calculations of Birds and Bacteria - Wired Science: We can now show that a single electronic excitation acting as a probability amplitude wave can simultaneously sample the various molecular paths connecting the antenna cells to the reaction center. The excitation effectively “picks” the most efficient route from leaf surface to sugar conversion site from a quantum menu of possible paths. This requires that all possible states of the traveling particle be superposed in a single, coherent quantum state for tens of femtoseconds.

We have seen this remarkable phenomenon in the green sulphur bacteria, but humans have not yet figured out how it is that nature can stabilize a coherent electronic quantum state in such complex systems for such long periods of time...

Remarkably, it seems that these photosynthesizing bacteria can actually use decoherence to speed up the transfer of electronic information by accessing vibrational energies in the protein bath surrounding the biological-quantum wire without losing the integrity of the information...

It seems that quantum mechanical processes in the avian eye send signals to the brain that are sensitively dependent on the angle of change in magnetic field inclination, thereby allowing the bird to map routes. The hypothesis is that pairs of light-absorbing molecules in the bird retina produce quantum mechanically entangled electrons whose quantum mechanical state depends on the angular inclination of the field and which catalyze chemical reactions that send differently valued signals to the brain depending upon the degree of inclination.

UEA scientists mimic nature in �800,000 renewable energy project - University of East Anglia (UEA)

UEA scientists mimic nature in �800,000 renewable energy project - University of East Anglia (UEA): “Light absorption by the green chlorophyll pigments generates an energised electron that is directed, along chains of metal centres, to catalysts that make sugars.

“We will build a system for artificial photosynthesis by placing tiny solar-panels on microbes. These will harness sunlight and drive the production of hydrogen, from which the technologies to release energy on demand are well-advanced.

“We imagine that our photocatalysts will prove versatile and that with slight modification they will be able to harness solar energy for the manufacture of carbon-based fuels, drugs and fine chemicals.”

Entanglement Makes Quantum Batteries Almost Perfect, Say Theorists | MIT Technology Review

Entanglement Makes Quantum Batteries Almost Perfect, Say Theorists | MIT Technology Review: Alicki and Fannes show that when quantum batteries are entangled they become much better. That’s essentially because all the energy from all the batteries can be extracted at once...
In fact, as the number of entangled batteries increases, the performance becomes arbitrarily close to the thermodynamic limit...
...Quantum batteries in the form of atoms or molecules may be ubiquitous in nature, in processes such as photosynthesis. Biologists know for example that during photosynthesis, energy is transferred with 100 per cent efficiency from one molecular machine to another.
How this happens, nobody knows.

Quantum Dots Make Artificial Photosynthesis Last Longer

Quantum Dots Make Artificial Photosynthesis Last Longer: ...One approach involves using particles that combine light-absorbing materials with catalysts that can split water. But the light-absorbing materials tend to deteriorate quickly in sunlight, rendering the approach impractical.

In the latest issue of the journal Science, researchers from the University of Rochester show that quantum dots not only absorb the light but also are far more durable than previous light-absorbing materials. The new approach also has the advantage of not requiring any precious metals, so it might be relatively cheap.

Artificial Photosynthesis Effort Takes Root

Artificial Photosynthesis Effort Takes Root: To speed up materials discovery, researchers at the Caltech hub, who collaborate with researchers at Lawrence Berkeley National Lab and more than 20 other research centers, have developed an ink-jet printing process that can churn out millions of slightly different variations on promising catalysts. Each sample is as small as a pixel on a screen. They're also developing equipment that can quickly test the activity of each catalyst. "It will dramatically accelerate the rate of electrocatalyst and photocatalyst discovery from a few candidates a year to a few every few milliseconds, producing thousands to millions per day..."

Panasonic Touts Artificial Photosynthesis Technology - Technology Review

Panasonic Touts Artificial Photosynthesis Technology - Technology Review: Panasonic's approach relies on a nitride semiconductor in the presence of light to produce a flow of electrons and split water into hydrogen and oxygen. Using a semiconductor in sunlight changes the energy state of CO2 and makes it suitable to conversion into other more valuable, organic molecules, according to Panasonic. A second reaction uses a metal catalyst to combine the "reduced" CO2 and hydrogen to make formic acid, a chemical used in the production of textiles and dyes.

The efficiency of the conversion of water, CO2, and sunlight to formic acid is 0.2 percent, which is not high enough for commercial use.

Photosynthesis re-wired: Chemists use nanowires to power photosynthesis

Photosynthesis re-wired: Chemists use nanowires to power photosynthesis: The process succeeds in taming stubborn carbon, which structurally resists most efforts to harness it for a single chemical product. Typically, refined forms of carbon molecules must first be produced to produce the necessary results.
"If we can start to use carbon dioxide and light to power reactions in organic chemistry, there's a huge benefit to that. It allows you to bypass the middle man of fossil fuels by using light to drive the chemical reaction," said Tan. "The key is the interaction of two fields – materials and synthetic chemistry..."

Biophoton Communication: Can Cells Talk Using Light? - Technology Review

Biophoton Communication: Can Cells Talk Using Light? - Technology Review: Mayburov has spent many hours in the dark watching fish eggs and recording the patterns of biophotons that these cells emit.
The question he aims to answer is whether the stream of photons has any discernible structure that would qualify it as a form of communication.
The answer is that is does, he says. Biophoton streams consist of short quasiperiodic bursts, which he says are remarkably similar to those used to send binary data over a noisy channel. That might help explain how cells can detect such low levels of radiation in a noisy environment...

In several experiments, biophotons from a growing plant seem to increase the rate of cell division in other plants by 30 per cent...
Other experiments have shown that the biophotons from growing eggs can encourage the growth of other eggs of a similar age.

Nano-Engineered Bioconstructs Perform Photosynthesis Faster Than Nature Does | Popular Science

Nano-Engineered Bioconstructs Perform Photosynthesis Faster Than Nature Does | Popular Science: Researchers led by Carolyn Lubner at Penn State worked with a cyanobacterium called Synechococcus and another bacterium, Clostridium acetobutylicum. In nature, photosynthetic organisms use light-capturing enzymes nicknamed Photosystem I and II, which absorb light and excite electrons to a higher energy state. Another enzyme called FNR then uses these electrons to produce an energy-storage molecule. This molecule is used to make sugars to keep the organism alive, and that's your basic photosynthesis process.
Lubner et al replaced the FNR enzyme with a hydrogenase enzyme, which combines electrons with hydrogen ions to make molecular hydrogen (instead of a sugar-producing system). Then they used this enzyme to stitch together iron-based terminals of a Photosystem I enzyme from each of the bacteria. This stitch served as a molecular wire, easily and quickly transferring electrons. The researchers doped it with vitamin C, which served as the electron feedstock.
The result was a high-throughput hydrogen-producing system — electron flow was more than twice as high as the bacteria’s individual rates, the authors say.

More evidence found for quantum physics in photosynthesis

More evidence found for quantum physics in photosynthesis: In an experiment published Dec. 6 in Proceedings of the National Academy of Sciences, a connection between coherence—far-flung molecules interacting as one, separated by space but not time—and energy flow is established.

..."Here we can watch the relationship between coherence and energy transfer. This is the first paper showing that coherence affects the probability of transport. It really does change the chemical dynamics."

...Energy from incoming photons could simultaneously explore every possible chlorophyll route from a protein's surface to the reaction center at its core, then settle on the shortest path.


...a team... analyzed the fluctuation of lasers as they passed through antenna proteins. Depending on how they shifted, the researchers could track what happened inside.

They found a clear mathematical link between energy flows and fluctuations in chlorophyll coherence. The link was so clear it could be described in derivative sines and cosines, mathematical concepts taught in college trigonometry.

Life-like cells are made of metal - New Scientist - New Scientist

Life-like cells are made of metal: "I am 100 per cent positive that we can get evolution to work outside organic biology," says Lee Cronin (see photo, right) at the University of Glasgow. His building blocks are large "polyoxometalates" made of a range of metal atoms – most recently tungsten – linked to oxygen and phosphorus. By simply mixing them in solution, he can get them to self-assemble into cell-like spheres.

A blue-green revolution: Upgrading photosynthesis - environment - 22 February 2011 - New Scientist

A blue-green revolution: Upgrading photosynthesis:Plants pirated the machinery they use for photosynthesis from bacteria more than a billion years ago. The same machinery is found in every single plant today, from tiny insect-eating sundews to colossal redwood trees - and it has barely changed. For all the architectural complexity that plants have evolved, they are still powered by the same engine they have had from the beginning. That's a bit like building a modern aircraft carrier and powering it with a Victorian steam engine.

By contrast, while photosynthetic bacteria don't look like they have changed much, some have made big improvements under the hood. They can convert carbon dioxide into food far more efficiently than most plants, and many are also able to make their own nitrogen fertiliser. If crop plants could be upgraded with just some of the improved machinery found in modern bacteria, agriculture could be revolutionised once again.

Power Plants: Engineers Mimic Photosynthesis to Harvest Light Energy: Scientific American

Power Plants: Engineers Mimic Photosynthesis to Harvest Light Energy: Scientific American: Earlier research found that photosynthesis takes advantage of an effect known as quantum coherence. In one study researchers found that the energy absorbed by a chromophore travels through multiple networks at the same time in order to take the quickest path. Other research observed that "noise," or random fluctuations, at the quantum level helps move energy from chromophores to the reaction centers of photosynthesis. Building on this work, Cao and M.I.T. chemist Robert Silbey modeled a light-harvesting system in green sulfur bacteria and found that photosynthesis is most efficient when there is an intermediate amount of noise in the system. "In experimental conditions one always tries to reduce noise," Cao says, "but in a quantum mechanical system, it's actually useful to have some noise."

Dueling dipoles: In search of a new theory of photosynthetic energy transfer

Dueling dipoles: In search of a new theory of photosynthetic energy transfer: The first step in designing such a complex involved the use of Förster theory to calculate the efficiency of energy transfer between dyes. This theory posits that intermolecular energy transfer occurs when oscillating dipoles – chemical compounds that carry spatially separated and opposite electric charges – cause adjacent dipoles to oscillate in their turn. Dipole orientation plays a crucial role in the process. Orthogonally oriented dipoles are assumed to be incapable of energy transfer. If molecules are oriented in parallel, energy transfer is allowed.

To everyone's surprise, the measurements actually showed that energy can be transferred between orthogonally arranged chromophores with almost 100% efficiency. As Langhals emphasizes: "The process is extraordinarily efficient. This is reflected in the extremely short reaction time – 9.4 billionths of a second. The findings rule out the idea that energy transfer occurs by a dipole-based mechanism. Instead, our results imply a low-frequency mode of coupling via intramolecular vibrations."

Fine-tuning photosynthesis

Fine-tuning photosynthesis: "In the related work published last month, Cao, Class of 1942 Professor of Chemistry Robert Silbey, and their postdoctoral fellow, Jianlan Wu, had found that the efficiency of natural photosynthesis can be improved by adding just the right amount of noise — that is, random fluctuations. Since noise usually reduces efficiency, this finding was somewhat counter-intuitive. Adding more noise could also decrease the efficiency, they found. “There’s an optimum amount” of noise, Silbey explains, that produces the most efficient transfer of energy."

CBC News - Technology & Science - Quantum 'weirdness' used by plants, animals

CBC News - Technology & Science - Quantum 'weirdness' used by plants, animals: "Lloyd said he got into the area about 3� years ago when someone in his lab found an article in the New York Times about researchers in Berkeley, Calif., who claimed green sulphur bacteria were performing a type of quantum calculation called a quantum search process while using photosynthesis to turn sunlight into energy."

Bio meets nano: Quantum dots as light antennas for artificial photosynthetic systems

Bio meets nano: Quantum dots as light antennas for artificial photosynthetic systems: In organisms, the first step of photosynthesis is the absorption of light by an antenna, a complex of proteins and pigments that is brought into an electronically excited state by light energy. The energy packet can then be passed on to special chlorophyll cofactors in the reaction center of the photosynthetic apparatus. There the energy is finally used to produce cellular energy stores such as ATP. The passing-on of the energy packets occurs through a special radiation-free process called Förster resonance energy transfer (FRET), in which the electronic states of the sender and receiver of the energy packets must be brought into resonance.