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porphyrin
porphyrin Any of a group of organic pigments characterized by the possession of a cyclic group of four linked nitrogen-containing rings (a tetrapyrrole nucleus), the nitrogen atoms of which are often coordinated to metal ions. Porphyrins differ in the nature of their side-chain groups. They include the chlorophylls, which contain magnesium; and haem, which contains iron and forms the prosthetic group of haemoglobin, myoglobin, and the cytochromes.
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"porphyrin." A Dictionary of Biology. 2004. Encyclopedia.com. 31 May. 2012 <http://www.encyclopedia.com>. "porphyrin." A Dictionary of Biology. 2004. Encyclopedia.com. (May 31, 2012). http://www.encyclopedia.com/doc/1O6-porphyrin.html "porphyrin." A Dictionary of Biology. 2004. Retrieved May 31, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O6-porphyrin.html |
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porphyrin
porphyrin Heterocyclic derivative of a porphin, which is composed of four linked rings, each containing nitrogen (a tetrapyrrole ring structure). As such it is capable of combining with a variety of metals and so forms part of the structure of many important biological molecules, including haemoproteins, chlorophyll, cytochromes, and vitamin B12.
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AILSA ALLABY and MICHAEL ALLABY. "porphyrin." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 31 May. 2012 <http://www.encyclopedia.com>. AILSA ALLABY and MICHAEL ALLABY. "porphyrin." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (May 31, 2012). http://www.encyclopedia.com/doc/1O13-porphyrin.html AILSA ALLABY and MICHAEL ALLABY. "porphyrin." A Dictionary of Earth Sciences. 1999. Retrieved May 31, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-porphyrin.html |
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porphyrin
porphyrin (por-fi-rin) n. one of a number of pigments derived from porphin, which are widely distributed in living things. All porphyrins form chelates with iron, magnesium, zinc, nickel, copper, and cobalt. These chelates are constituents of haemoglobin, myohaemoglobin, the cytochromes, and chlorophyll. See also protoporphyrin IX.
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"porphyrin." A Dictionary of Nursing. 2008. Encyclopedia.com. 31 May. 2012 <http://www.encyclopedia.com>. "porphyrin." A Dictionary of Nursing. 2008. Encyclopedia.com. (May 31, 2012). http://www.encyclopedia.com/doc/1O62-porphyrin.html "porphyrin." A Dictionary of Nursing. 2008. Retrieved May 31, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O62-porphyrin.html |
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porphyrin
porphyrin A heterocyclic derivative of a porphin, which is composed of a tetrapyrrole ring structure. As such it is capable of combining with a variety of metals and so forms part of the structure of many important biological molecules, including haemoproteins, chlorophyll, vitamin B12, and cytochromes.
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Cite this article
MICHAEL ALLABY. "porphyrin." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. 31 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "porphyrin." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. (May 31, 2012). http://www.encyclopedia.com/doc/1O7-porphyrin.html MICHAEL ALLABY. "porphyrin." A Dictionary of Plant Sciences. 1998. Retrieved May 31, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O7-porphyrin.html |
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porphyrin
porphyrin A heterocyclic derivative of a porphin, which is composed of a tetrapyrolle ring structure. As such it is capable of combining with a variety of metals and so forms part of the structure of many important biological molecules, including haemoproteins, chlorophyll, vitamin B12, and cytochromes.
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Cite this article
MICHAEL ALLABY. "porphyrin." A Dictionary of Zoology. 1999. Encyclopedia.com. 31 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "porphyrin." A Dictionary of Zoology. 1999. Encyclopedia.com. (May 31, 2012). http://www.encyclopedia.com/doc/1O8-porphyrin.html MICHAEL ALLABY. "porphyrin." A Dictionary of Zoology. 1999. Retrieved May 31, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-porphyrin.html |
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