Sunday, 21 June 2009

Behind The Green Door

In simple terms, photosynthesis is the way green plants use light to convert water and carbon dioxide (CO2) into the simple sugar - glucose. Photosynthesis requires a source of hydrogen with which to reduce carbon dioxide into carbohydrates. The plant does this by splitting water into it's bare components - hydrogen and oxygen - in a process known as photolysis.

Photolysis of water occurs in the thylakoids of cyanobacteria and the chloroplasts of green algae and plants. Chloroplasts are the oval shaped structures found in the cells of plant leaves. Chlorophyll is found in high concentrations in the chloroplasts of plant cells. Chlorophyll is a green pigment that is responsible for trapping sunlight so that photosynthesis can take place.

The green colour in chlorophyll is thought to be due to a magnesium atom (well, rather a magnesium ion) surrounded by a nitrogen-containing group of atoms called a porphyrin ring. The structure somewhat resembles that of the active constituent of hemoglobin in the blood. A long chain of carbon and hydrogen atoms proceeds from this central core and attaches the chlorophyll molecule to the inner membrane of the chloroplast, the cell organelle in which photosynthesis takes place.

There are several publications concerning investigations of the electrochemical and electro-catalytical properties of porphyrin compounds. The reasons for this considerable interest in porphyrins and their metal complexes are their semiconductive, photosensitivity and catalytic properties as well as the possibility of modifying these properties by structural modification of the porphyrin ring.

We are told that chlorophyll "absorbs" all the other colours of the spectrum yet reflects green light - and that is why plants appear green. Perhaps though, chlorophyll does not so much as absorb other colours of the spectrum, maybe green is the only colour it emits. All matter emits electromagnetic radiation (EMR) - it just so happens that chlorophyll chooses to do so in the range of the spectrum which we percieve as green.

All matter emits EMR. The electric fluid of the aether moves through molecules. The molecules are static in the aether field - it is the aether which is in motion. It is this motion around molecules which generates EMR. Which says something pretty interesting about colour does it not? A substance does not absorb, and reflect light to create the colours that we see. What we are seeing is light being emitted by the substance.

Sunlight does not create the colours that we see, but rather it acts as a torchlight over something which already exists. Erm... so I now find myself, somewhat surreal as it is, saying that there's no such thing as "white light". Can I say that? Just thinking that there's no such thing as white light makes me feel like I just let one rip at the boss's dinner table. I feel dirty.

I'm not saying that plants don't utilise sunlight in some way for photosynthesis - based on the evidence that would be a bit silly - but I don't think sunlight provides the energy as such. The energy is already here in the aether field. I think of sunlight as more of a signal for a plant to rev its engine, so to speak.

In 1792 Volta stated that "metals are thus not only perfect conductors, but motors of electricity". Now, wouldn't it be interesting if the metal at the centre of the porphyrin ring is, in someway, acting through the aether as a motor of electricity? Perhaps it is this electricity which orchestrates the photolysis in which water is split into hydrogen and oxygen.

The same year that Volta announced the voltaic pile, Anthony Carlisle and William Nicholson used it to decompose water into hydrogen and oxygen in a process which has come to be known as electrolysis. Nicholson and Carlisle used platinum electrodes and separate tubes to collect the gases evolved at each electrode. Hydrogen gas bubbled from around the cathode and oxygen gas from around the anode in the ratio of two volumes of H2 for every volume of O2.

This reaction can be done in pure water, and not necessarily an ionic solution, because the platinum acts as an electrocatalyst. There's something else though ...because the platinum acts as a catalyst, if the electric supply is removed, the gas bubbles of hydrogen and oxygen found at the electrodes begin to recombine to form water again, and in this reaction they produce electricity. It appears as if the gas bubbles are storing electricity! The following site illustrates this experiment very nicely:

We've seen photosynthesis where plants take in carbon dioxide and water, and using the sun, these two gases combine in a chemical reaction to produce glucose and oxygen. The plant stores the glucose and releases the oxygen. The plant actively gets rid of the oxygen as waste. It does look a bit like the plant is storing electricity, or at least one half of the electrochemical reaction, in the form of hydrogen - which it then "hides" inside glucose. To release the electrical energy, the plant needs only to introduce oxygen to the hydrogen.

This process of using oxygen to release energy from glucose is called cellular respiration. Cellular respiration occurs in the mitochondria of the plant cell. The glucose molecule, using oxygen, is broken apart and turned back into carbon dioxide and water, the same types of molecules that originally combined to make the glucose. By recombining the oxygen and hydrogen the plant is generating electricity! And so I'm thinking, that maybe, this is what life is all about - all these reactions between carbohydrates and enzymes and lipids and the like - are really all part of an elaborate sequence which stores and then manipulates the availability of the electrical forces found inside water.

A conventional hydrogen fuel cell works by exploiting the mutual attraction of hydrogen and oxygen to produce electricity and water. At the moment, the hydrogen economy champions a PEM, or proton exchange membrane, fuel cell as the future. The PEM still depends on the simple chemical reaction between hydrogen and oxygen. The current version works well in hybrid autos, but users are for the most part limited to using pure hydrogen. That means somewhere, someplace else, water has to be electrolyzed to generate hydrogen. Once we have the hydrogen, then there is the also the problem of storing it, and distributing it. These aren't my thoughts particularly on the subject, but some see the beckoning hydrogen economy as a bit of a faux-pas:

The laws of physics mean the hydrogen economy will always be an energy sink. Hydrogen’s properties require you to spend more energy to do the following than you get out of it later: overcome waters’ hydrogen-oxygen bond, to move heavy cars, to prevent leaks and brittle metals, to transport hydrogen to the destination. It doesn’t matter if all of the problems are solved, or how much money is spent. You will use more energy to create, store, and transport hydrogen than you will ever get out of it.

Wouldn't be a lot more fun if the water itself was the fuel - as seems to be the case in nature? We would have only to fill our tanks with water, and then continously split the water to recombine the hydrogen and oxygen to generate electricity. The only waste product being water - which could quite merrily go back inside the fuel tank - no problemos.

A penny for my thoughts? It appears that an important part of photolysis is the pigment. I think I need to examine pigments elsewhere throughout nature, and amongst them, I wonder what is the exact impact of a porphyrin ring. Examples that stand out for me are those that are in the skin and in the blood. I'm also interested in understanding the role of pigments in everyday objects.

In cellular respiration, plants use oxygen to release energy from glucose in the process called aerobic respiration. I'm interested in how, exactly, the plant gains this oxygen. Is the plant able to use the oxygen it released via photosynthesis? Or does it absorb oxygen directly from the air through its leaves, or from water via the roots, or where?

Some plants photosynthesize using the CAM (crassulacean acid metabolism) mechanism. CAM plants live in very arid conditions. Unusually the stomata, the tiny pores on leaves, open at night (when evaporation rates are usually lower) and are usually closed during the day. The CO2 is converted to an acid and stored during the night. During the day, the acid is broken down and the CO2 is released to RUBISCO for photosynthesis.

It gets interesting when the plant suffers particularly dry weather, and tries to retain all its moisture by closing the stomata all night and day. Basically, oxygen given off in photosynthesis is used for respiration and CO2 given off in respiration is used for photosynthesis - but that sounds a bit like a perpetual energy machine, don't it?

Many thanks:

Encyclopedia of science and technology By James S. Trefil, Harold Morowitz, Paul Ceruzzi

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