PHOTOSYNTHESIS, process by which green plants and certain other organisms use the energy of light to convert dioxide and water into the simple sugar glucose. In so doing, photosynthesis provides the basic energy source for virtually all organisms. An extremely important byproduct of photosynthesis is oxygen, on which most organisms depend. Photosynthesis occurs in green plants, seaweeds, algae and certain bacteria. These organisms are veritable sugar factories, producing millions of new glucose molecules per second. Plants use much of this glucose, a carbohydrate, as an energy source to build leaves, flowers, fruits, and seeds. They also convert glucose to cellulose, the structural material used in their cell walls. Most plants produce more glucose than they use, and store it in the form of starch and other carbohydrates in roots, stems, and leaves. The plants can then draw on these reserves for extra energy or building materials. Plant photosynthesis occurs in leaves and green stems within specialized cell structures called chloroplasts. One plant leaf is composed of tens of thousands of cells, and each cell contains 40 to 50 chloroplasts. The chloroplast, an oval-shaped structure, is divided by membranes into numerous disk-shaped compartments. These disklike compartments, called thylakoids, are arranged vertically in the chloroplast like a stack of plates or pancakes. A stack of thylakoids is called a granum (plural, grana); the grana lie suspended in a fluid known as stroma. Embedded in the membranes of the thylakoids are hundreds of molecules of chlorophyll, a light-trapping pigment required for photosynthesis. Additional light-traping pigments, enzymes (organic substances that speed up chemical reactions), and other molecules needed for photosynthesis are also located within the thylakoins membranes. The pigments and enzymes are arranged in two types of units, Photosystem 1 and photosystem 2. Photosynthesis is a very complex process, and for the sake of convenience and ease of understanding, plant biologists divide it into two stages. In the first stage, the light-dependent reaction, the chloroplast traps light energy and converts it into two stages. In the first stage, the light-dependent reaction, the chloroplast traps light energy and converts it into chemical energy contained in nicotinamide adenine dinucleotide phosphate (NADPH) and adenosine triphosphate (ATP), two molecules used in the second stage of photosynthesis. In the second stage of photosynthesis. In the second stage, called the light-independent reaction (formerly called the dark reaction) NADPH provides the hydrogen atoms that help from glucose. These two stages reflect the literal meaning of the term photosysthesis, to build with light. Light contains many colors, each with a defined range of wavelengths measured in nanometers, or billionths of a meter. certain red and blue wavelengths of light are the most effective in photosynthesis because they have exactly the right amount of energy to energize, or excite, chlorophyll electrons and boost them out of their orbits to higher energy level. Other pigments, called accessory pigments, enhance the light-absorption capacity of the leaf by capturing a broader spectrum of blue and red wavelengths, along with yellow and orange wavelengths. None of the photosynthetic pigments absorb green light; as a result, green wavelengths are reflected, which is why plants appear green. The transfer of electrons in a step-by-step fashion in photosystems 1 and 2 releases energy and heat slowly, thus protecting the chloroplast and cell from a harmful temperature increase. It also provides time for the plant to from NADPH and ATP. In the words of American biochemist and Nobel laureate Albert Szent-Gyorgyi, ” What drives life is thus a little electric current, set up by the sunshine.” The chemical energy required for the light-independent reaction is supplied by the ATP and NADPH molecules produced in the light-dependent reaction. The light-independent reaction is cyclic, that is, it begins with a molecule that must be regenerated at the end of the reaction in order for the process to continue. Termed the Calvin cycle after the American chemist Melvin Calvin who discovered it, the light-independent reactions use the electrons and hydrogen ions associated with NADPH and the phosphorus associated with ATP to produce glucose. These reactions occur in the stroma, the fluid in the chloroplast surrounding the thylakoids, and each step is controlled by a different enzyme. The light-independent reaction requires the presence of carbon dioxide molecules, which enter the plant through pores in the leaf, diffuse through the cell to the chloroplast, and disperse in the stroma. The light-independent reaction begins in the stroma when these carbon dioxide molecules link to suger molecules called ribulose bisphosphate (RuBP) in a process known as carbon fixation. Ok while it may seem that we understand photosynthesis in detail, decades of experiments have given us only a partial understanding of this important process.
For about the last 50 years, farmers around the world have used synthetic nitrogen fertilizers to boost their crop yields and drive the 20th century’s rapid agricultural intensification…But in their fervor to increase yields, farmers often dose their crops with more nitrogen than the plants can absorb.
The total amount of nitrogen that is put on the land is about three times as much as their actually removing from the land in terms of harvest. Most of it ends up as runoff, or collects in lagoons, where it ultimately leaches into the water table. The impacted communities are about as visible as an underground water table.
This lack of visibility doesn’t make the problem any less pronounced. Many residents in these town’s spend up to a fifth of their income on bottled water, which is in addition to the $60 a month they must spend to have contaminated “drinking water” delivered to their home in the first place. If you don’t break out in welts after bathing, “you are still inhaling the toxins through the steam of the shower, many people think that boiling the water will rid it of nitrates when in fact doing so triples the concentration.
The excess is now causing serious air and water pollution and threatening human health. Grow Switch believes that a core shift in farm practices with conventional farming will be crucial to stopping the pollution from getting worse.
Soil pH is a relative measure of the hydrogen ion concentration (H+) in the soil. The pH value can vary from a minimum value of 0 to a maximum value of 14.
Cation exchange capacity (CEC) is a measure of the total amount of exchangeable cations (positively charged ions) a soil can adsorb. Nutrient cations in the soil include positively charged ions such as calcium (Ca+2), magnesium (Mg+2), potassium (K+), sodium (Na+) and hydrogen (H+).
Anions are negatively charged ions.
Anions such as nitrate (NO3-), sulfate (SO4-) and chloride (Cl-) are highly soluble and move with water.
The phosphate anion (PO3-) does not move freely in soils largely because it forms relatively insoluble compounds with iron and aluminum in acid soils (low pH) and with calcium in alkaline soils (high pH). Seventeen elements are considered essential nutrients for plant growth.
If there is a deficiency of any essential element, plants cannot complete their vegetative or reproductive cycles. Some of these nutrients combine to form compounds that make up cells and enzymes. Other nutrients are necessary for certain chemical processes to occur. The most limiting nutrient in a soil determines the growth and reproduction of plants.
Nitrogen is a building block of plant proteins. It is an integral part of chlorophyll and is a component of amino acids, nucleic acids and coenzymes. Most nitrogen in the soil in tied up in organic matter. It is taken up by plants as nitrate (NO3-).
Plants use phosphorus to form the nucleic acids DNA and RNA and to store and transfer energy. Phosphorus promotes early plant growth and root formation through its role in the division and organization of cells. Phosphorus is essential to flowering and fruiting and to the transfer of hereditary traits. Phosphorus is adsorbed by plants as H2PO4-, HPO4-2 or PO-3,depending upon soil pH.
Potassium is necessary to plants for translocation of sugars and for starch formation. It is important for efficient use of water through its role in opening and closing small apertures (stomata) on the surface of leaves. Phosphorus increases plant resistance to diseases and assists in enzyme activation and photosynthesis. It also increases the size and quality of fruits or flowers. Plants take up potassium in the form of potassium ions (K+).
Calcium provides a building block (calcium pectate) for cell walls and membranes and must be present for the formation of new cells. It is a constituent of important plant carbohydrates, such as starch and cellulose. Calcium promotes plant vigor and rigidity and is important to proper root and stem growth. Plants adsorb calcium in the form of the calcium ion (Ca+).
Magnesium is a component of the chlorophyll molecule and is therefore essential for photosynthesis. Magnesium serves as an activator for many plant enzymes required for sugar metabolism and movement and for growth processes. Plants take up magnesium as the Mg+2 ion.
Sulfur is a constituent of three amino acids (cystine, methionine and cysteine) that play an essential role in protein synthesis. Sulfur is present in oil compounds responsible for characteristic odors of plants. It is also essential for nodule formation on legumes. Plants take up sulfur in the form of sulfate (SO4-2) ions.
Zinc is an essential component of several enzymes in plagrowth regulator, and it is involved in the production of chlorophyll and protein. Zinc is taken up by plants as the zinc ion (Zn+2).
Iron is taken up by plants as ferrous ion (Fe+2). Iron is required for the formation of chlorophyll in plant cells. It serves as an activator for biochemical processes such as respiration, photosynthesis and symbiotic nitrogen fixation.
Manganese serves as an activator for enzymes in plant growth processes, and it assists iron in chlorophyll formation. Plants obtain this nutrient from the soil in the form of manganous ion (Mn+2).
Copper is an activator of several enzymes in plants. It may play a role in production of vitamin A. Deficiency interferes with protein synthesis. Copper deficiencies are not common in soils. Plants take up copper from the soil in the form of cuprous (Cu+) or cupric (Cu+2) ions.
Boron regulates the metabolism of carbohydrates in plants. It is essential for the process by which meristem cells (cells that divide) differentiate to form specific tissues. With boron deficiency, plant cells may continue to divide, but structural components are not differentiated. Boron is taken up by plants as the borate ion (BO3-).
Molybdenum is taken up by plants as molybdate ions (MoO4-). Molybdenum is an essential micronutrient that enables plants to make use of nitrogen. Without molybdenum, plants cannot transform nitrate nitrogen to amino acids and legumes cannot fix atmospheric nitrogen. Chlorine Chlorine is required in photosynthetic reactions. Plants take up chlorine as chloride ion (Cl-).
Nickel is taken up by plants as Ni+2. Nickel is a component of the enzyme urease,
Hydroponic mediums, moss, coco, perlite, hardened expanded clay, vermiculite, rockwool and neoprene discs, are some of our non-organic mediums or non-mineral soils, used in hydroponics, the difference between soil and non-soil mediums is their ability to hold water and oxygen, and their ability to hold onto nutrient ions and supply them to the plant roots as the plants call for them. (CEC) Cation exchange capacity is the ability of a growing medium to hold nutrients on call for the roots to uptake. The CEC of each medium will affect the pH for maximum nutrient uptake.
Regular dirt soils with their particle charges electrically hold nutrients readily available for the roots. they have high CECs between 100-200 equivalent units. Vermiculite and peat moss mixes have CECs of 50-60 equivalent units. Rockwool, perlite, and water cultures have a CEC of 0 they do not hold nutrients on call for the roots to uptake, and once a nutrient has passed by, it is gone. it also means that these mediums have no buffering effect.
A cation is an ion with a positive electro-magnetic charge. FULL ON is comprised of exceptionally tiny particles called “colloidal micelles.” Each micelle carries a negative electro-magnetic charge that is capable of attracting, holding and exchanging positively charged particles (cations) of carbon, calcium, humus, magnesium, trace minerals and other nutrients and moisture allowing roots to more easily absorb them. This phenomenon is called “cation exchange.” FULL ON enhances Cation Exchange Capacity.