Chlorophyll gives leaves their green color

Space-filling model of the chlorophyll molecule

Chlorophyll is found in high concentrations in chloroplasts of plant cells.

Absorbance spectra of free chlorophyll a (green) and b (red) in a solvent. The spectra of chlorophyll molecules are slightly modified in vivo depending on specific pigment-protein interactions.

Chlorophyll is a green pigment found in most plants, algae, and cyanobacteria. Its name is derived from ancient Greek: chloros = green and phyllon = leaf. Chlorophyll absorbs light most strongly in the blue and red but poorly in the green portions of the electromagnetic spectrum, hence the green color of chlorophyll-containing tissues like plant leaves. Image File history File links Leavessnipedale. ... Image File history File links Leavessnipedale. ... Image File history File links Download high-resolution version (1100x694, 155 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Chlorophyll ... Image File history File links Download high-resolution version (1100x694, 155 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Chlorophyll ... Image File history File linksMetadata No higher resolution available. ... Image File history File linksMetadata No higher resolution available. ... Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. ... This image is an edit of a graph that originally appeared in the Chlorophyll article. ... This image is an edit of a graph that originally appeared in the Chlorophyll article. ... In spectroscopy, the absorbance A is defined as , where is the intensity of light at a specified wavelength λ that has passed through a sample (transmitted light intensity) and is the intensity of the light before it enters the sample or incident light intensity. ... Natural Ultramarine pigment in powdered form. ... For other uses, see Plant (disambiguation). ... A seaweed (Laurencia) up close: the branches are multicellular and only about 1 mm thick. ... Orders The taxonomy is currently under revision. ... For other uses, see Green (disambiguation). ... Look up foliage in Wiktionary, the free dictionary. ... Legend γ = Gamma rays HX = Hard X-rays SX = Soft X-Rays EUV = Extreme ultraviolet NUV = Near ultraviolet Visible light NIR = Near infrared MIR = Moderate infrared FIR = Far infrared Radio waves EHF = Extremely high frequency (Microwaves) SHF = Super high frequency (Microwaves) UHF = Ultra high frequency VHF = Very high frequency HF = High...

Chlorophyll and photosynthesis

Chlorophyll is vital for photosynthesis, which allows plants to obtain energy from light. Chlorophyll molecules are specifically arranged in and around pigment protein complexes called photosystems which are embedded in the thylakoid membranes of chloroplasts. In these complexes, chlorophyll serves two primary functions. The function of the vast majority of chlorophyll (up to several hundred per photosystem) is to absorb light and transfer that light energy by resonance energy transfer to a specific chlorophyll pair in the reaction center of the photosystems. Because of chlorophyll’s selectivity regarding the wavelength of light it absorbs, areas of a leaf containing the molecule will appear green. There are currently two accepted photosystem units, Photosystem II and Photosystem I, which have their own distinct reaction center chlorophylls, named P680 and P700, respectively.^[1] These pigments are named after the wavelength (in nanometers) of their red-peak absorption maximum. The identity, function and spectral properties of the types of chlorophyll in each photosystem are distinct and determined by each other and the protein structure surrounding them. Once extracted from the protein into a solvent (such as acetone or methanol), these chlorophyll pigments can be separated in a simple paper chromatography experiment, and, based on the number of polar groups between chlorophyll a and chlorophyll b, will chemically separate out on the paper. The function of the reaction center chlorophyll is to use the energy absorbed by and transferred to it from the other chlorophyll pigments in the photosystems to undergo a charge separation, a specific redox reaction in which the chlorophyll donates an electron into a series of molecular intermediates called an electron transport chain. The charged reaction center chlorophyll (P680⁺) is then reduced back to its ground state by accepting an electron. In Photosystem II, the electron which reduces P680⁺ ultimately comes from the oxidation of water into O₂ and H⁺ through several intermediates. This reaction is how photosynthetic organisms like plants produce O₂ gas, and is the source for practically all the O₂ in Earth's atmosphere. Photosystem I typically works in series with Photosystem II, thus the P700⁺ of Photosystem I is usually reduced, via many intermediates in the thylakoid membrane, by electrons ultimately from Photosystem II. Electron transfer reactions in the thylakoid membranes are complex, however, and the source of electrons used to reduce P700⁺ can vary. The electron flow produced by the reaction center chlorophyll pigments is used to shuttle H⁺ ions across the thylakoid membrane, setting up a chemiosmotic potential mainly used to produce ATP chemical energy, and those electrons ultimately reduce NADP⁺ to NADPH a universal reductant used to reduce CO₂ into sugars as well as for other biosynthetic reductions. The leaf is the primary site of photosynthesis in plants. ... REDIRECT [[In the process of photosynthesis, light is absorbed by a photosystem (ancient Greek: phos = light and systema = assembly) to begin an energy-producing reaction. ... Thylakoids (green) inside a chloroplast Thylakoids (green) inside a cyanobacterium (Synechocystis) A Thylakoid is a membrane-bound compartment inside chloroplasts and cyanobacteria. ... Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. ... Fluorescence resonance energy transfer (or Förster resonance energy transfer) describes an energy transfer mechanism between two fluorescent molecules. ... An electron micrograph of a series of reaction centres and light harvesting complexes from the surface of the thylakoid membrane inside a chloroplast. ... A nanometre (American spelling: nanometer) is 1. ... The chemical compound acetone (also known as propanone, dimethyl ketone, 2-propanone, propan-2-one and β-ketopropane) is the simplest representative of the ketones. ... Methanol, also known as methyl alcohol, carbinol, wood alcohol, wood naptha or wood spirits, is a chemical compound with chemical formula CH3OH. It is the simplest alcohol, and is a light, volatile, colourless, flammable, poisonous liquid with a distinctive odor that is somewhat milder and sweeter than ethanol (ethyl alcohol). ... Illustration of a redox reaction Redox (shorthand for oxidation/reduction reaction) describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed. ... For other uses, see Electron (disambiguation). ... The Electron Transport Chain. ... Chemiosmosis is the diffusion of ions across a membrane. ... Adenosine 5-triphosphate (ATP) is a multifunctional nucleotide that is most important as a molecular currency of intracellular energy transfer. ... Nicotinamide adenine dinucleotide (NAD+) Nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP) are two important coenzymes found in cells. ... Illustration of a redox reaction Redox (shorthand for oxidation/reduction reaction) describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed. ...

Reaction center chlorophyll-protein complexes are capable of directly absorbing light and performing charge separation events without other chlorophyll pigments, but the absorption cross section (the likelihood of absorbing a photon under a given light intensity) is small. Thus, the remaining chlorophylls in the photosystem and antenna pigment protein complexes associated with the photosystems all cooperatively absorb and funnel light energy to the reaction center. Besides chlorophyll a, there are other pigments, called accessory pigments, which occur in these pigment-protein antenna complexes. An accessory pigment is a pigment other than chlorophyll found in plants, such as a carotenoid, that serves the function of absorbing light energy, and transfering it to chlorophyll. ...

Chemical structure

Chlorophyll is a chlorin pigment, which is structurally similar to and produced through the same metabolic pathway as other porphyrin pigments such as heme. At the center of the chlorin ring is a magnesium ion. The chlorin ring can have several different side chains, usually including a long phytol chain. There are a few different forms that occur naturally, but the most widely distributed form in terrestrial plants is chlorophyll a. The general structure of chlorophyll a was elucidated by Hans Fischer in 1940, and by 1960, when most of the stereochemistry of chlorophyll a was known, Robert Burns Woodward published a total synthesis of the molecule as then known.^[2]. In 1967, the last remaining stereochemical elucidation was completed by Ian Fleming^[3], and in 1990 Woodward and co-authors published an updated synthesis.^[4] In organic chemistry, a chlorin is a large heterocyclic aromatic ring consisting, at the core, of 3 pyrroles and one reduced pyrrole coupled through 4 methine linkages. ... Structure of porphine, the simplest porphyrin. ... Structure of Heme b A heme or haem is a prosthetic group that consists of an iron atom contained in the center of a large heterocyclic organic ring called a porphyrin. ... General Name, symbol, number magnesium, Mg, 12 Chemical series alkaline earth metals Group, period, block 2, 3, s Appearance silvery white solid at room temp Standard atomic weight 24. ... Phytol is a natural linear diterpene alcohol which is used in the preparation of vitamins E and K1. ... Hans Fischer (July 27, 1881 – March 31, 1945) was a German organic chemist and the recipient of the 1930 Nobel Prize for Chemistry. ... Robert Burns Woodward (April 10, 1917–July 8, 1979) was an American organic chemist. ... This article is about the chemist. ...

The different structures of chlorophyll are summarized below:

Structure of chlorophyll a	Structure of chlorophyll b	Structure of chlorophyll d
Structure of chlorophyll c1	Structure of chlorophyll c2

Image File history File links Chlorophyll_a. ... Image File history File links Chlorophyll_a. ... Image File history File links Chlorophyll_b. ... Image File history File links Chlorophyll_b. ... Image File history File links Chlorophyll_d. ... Image File history File links Chlorophyll_d. ... Image File history File links Chlorophyll_c1. ... Image File history File links Chlorophyll_c1. ... Image File history File links Chlorophyll_c2. ... Image File history File links Chlorophyll_c2. ...

Spectrophotometry

Measurement of the absorption of light is complicated by the solvent used to extract it from plant material, which affects the values obtained,

• In diethylether, chlorophyll a has approximate absorbance maxima of 430 nm and 662 nm, while chlorophyll b has approximate maxima of 453 nm and 642 nm.^[5]
• The absorption peaks of Chlorophyll a are at 665 nm and 465 nm. Chlorophyll a fluoresces at 673 nm. The peak molar absorption coefficient of chlorophyll a exceeds 10⁵ M⁻¹ cm⁻¹, which is among the highest for organic compounds.

The molar extinction coefficient, also known as molar absorptivity, is a measure of how strongly a chemical species at a given wavelength absorbs light at that wavelength. ...

Chlorosis

Main article: Chlorosis

Chlorosis is a condition in which leaves produce insufficient chlorophyll, turning them yellow. Chlorosis can be caused by lack of iron, magnesium or nitrogen. In botany, Chlorosis is a condition in which plant foliage produces insufficient chlorophyll. ... Iron (Fe) deficiency is a plant disorder also known as ‘lime-induced chlorosis’. A deficiency in the soil is rare. ... Magnesium (Mg) deficiency is a plant disorder. ... Nitrogen (N) deficiency in plants can occur when woody material such as sawdust is added to the soil. ...

See also

• bacteriochlorophyll
• Grow light

Bacteriochlorophylls are photosynthetic pigments that occur in various bacteria. ... Grow lights are electric lamps designed to promote plant growth by emitting an electromagnetic spectrum appropriate for photosynthesis. ...

References

1. ^ Green, 1984
2. ^ R. B. Woodward, W. A. Ayer, J. M. Beaton, F. Bickelhaupt, R. Bonnett, P. Buchschacher, G. L. Closs, H. Dutler, J. Hannah, F. P. Hauck, S. Itô, A. Langemann, E. Le Goff, W. Leimgruber, W. Lwowski, J. Sauer, Z. Valenta, and H. Volz (1960). "The total synthesis of chlorophyll". Journal of the American Chemical Society 82: 3800-3802. 
3. ^ Ian Fleming (October 1967). "Absolute Configuration and the Structure of Chlorophyll". Nature 216: 151-152. doi:10.1038/216151a0. 
4. ^ Robert Burns Woodward, William A. Ayer, John M. Beaton, Friedrich Bickelhaupt, Raymond Bonnett, Paul Buchschacher, Gerhard L. Closs, Hans Dutler, John Hannah, Fred P. Hauck, et al. (1990). "The total synthesis of chlorophyll a". Tetrahedron 46 (22): 7599-7659. 
5. ^ Gross, 1991

• Speer, Brian R. (1997). "Photosynthetic Pigments" in UCMP Glossary (online). University of California, Berkeley Museum of Paleontology. Verified availability March 12, 2007.
• PDF review-Chlorophyll d: the puzzle resolved
• Light Absorption by Chlorophyll – NIH books

A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... is the 71st day of the year (72nd in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ...

External links

• Oregon University of Health & Sciences