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chlorophyll

or chlo·ro·phyl

[klawr-uh-fil, klohr-]
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noun Botany, Biochemistry.
  1. the green coloring matter of leaves and plants, essential to the production of carbohydrates by photosynthesis, and occurring in a bluish-black form, C55H72MgN4O5 (chlorophyll a), and a dark-green form, C55H70MgN4O6 (chlorophyll b).

Origin of chlorophyll

First recorded in 1810–20; chloro-1 + -phyll
Related formschlo·ro·phyl·loid, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for chlorophyll-b

chlorophyll

US chlorophyl

noun
  1. the green pigment of plants and photosynthetic algae and bacteria that traps the energy of sunlight for photosynthesis and exists in several forms, the most abundant being chlorophyll a (C 55 H 72 O 5 N 4 Mg): used as a colouring agent in medicines or food (E140)
Derived Formschlorophylloid, adjectivechlorophyllous, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for chlorophyll-b

chlorophyll

n.

green-colored stuff in plants, 1819, from French chlorophyle (1818), coined by French chemists Pierre-Joseph Pelletier (1788-1842) and Joseph Bienaimé Caventou (1795-1877) from Greek khloros "pale green" (see Chloe) + phyllon "a leaf" (see folio).

Online Etymology Dictionary, © 2010 Douglas Harper

chlorophyll-b in Medicine

chlorophyll

n.
  1. Any of a group of related green pigments found in photosynthetic cells that converts light energy into ATP and other forms of energy needed for biochemical processes; it is found in green plants, brown and red algae, and certain aerobic and anaerobic bacteria.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

chlorophyll-b in Science

chlorophyll

[klôrə-fĭl]
  1. Any of several green pigments found in photosynthetic organisms, such as plants, algae, and cyanobacteria. At its molecular core, chlorophyll has a porphyrin structure but contains a magnesium atom at its center and a long carbon side chain. Chlorophyll absorbs red and blue wavelengths of light, but reflects green. When it absorbs light energy, a chlorophyll molecule enters a higher energy state in which it easily gives up an electron to the first available electron-accepting molecule nearby. This electron moves through a chain of acceptors and is ultimately used in the synthesis of ATP, which provides chemical energy for plant metabolism. Plants rely on two forms of chlorophyll, chlorophyll a (C66H72MgN4O5) and chlorophyll b (C66H70MgN4O6), which have slightly different light absorbing properties. All plants, algae, and cyanobacteria have chlorophyll a, since only this compound can pass an electron to acceptors in oxygen-producing photosynthetic reactions. Chlorophyll b absorbs light energy that is then transferred to chlorophyll a. Several protist groups such as brown algae and diatoms lack chlorophyll b but have another pigment, chlorophyll c, instead. Other closely related pigments are used by various bacteria in photosynthetic reactions that do not produce oxygen. See more at photosynthesis.
Word History: From its name, one might think that chlorophyll has chlorine in it, but it doesn't. The chloro- of chlorophyll comes from the Greek word for “green”; chlorophyll in fact is the chemical compound that gives green plants their characteristic color. The name of the chemical element chlorine comes from the same root as the prefix chloro-, and is so called because it is a greenish-colored gas.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

chlorophyll-b in Culture

chlorophyll

[(klawr-uh-fil)]

The complex chemical that gives a plant its green color and plays an important role in the conversion of sunlight into energy for the plant. (See photosynthesis.)

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.