<P> After initial work done by German chemist Richard Willstätter spanning from 1905 to 1915, the general structure of chlorophyll a was elucidated by Hans Fischer in 1940 . By 1960, when most of the stereochemistry of chlorophyll a was known, Robert Burns Woodward published a total synthesis of the molecule . In 1967, the last remaining stereochemical elucidation was completed by Ian Fleming, and in 1990 Woodward and co-authors published an updated synthesis . Chlorophyll f was announced to be present in cyanobacteria and other oxygenic microorganisms that form stromatolites in 2010; a molecular formula of C H O N Mg and a structure of (2 - formyl) - chlorophyll a were deduced based on NMR, optical and mass spectra . </P> <P> Chlorophyll is vital for photosynthesis, which allows plants to absorb energy from light . </P> <P> Chlorophyll molecules are arranged in and around photosystems that are embedded in the thylakoid membranes of chloroplasts . In these complexes, chlorophyll serves three functions . The function of the vast majority of chlorophyll (up to several hundred molecules per photosystem) is to absorb light . Having done so, these same centers execute their second function: the transfer of that light energy by resonance energy transfer to a specific chlorophyll pair in the reaction center of the photosystems . This pair effects the final function of chlorophylls, charge separation, leading to biosynthesis . The two currently accepted photosystem units are photosystem II and photosystem I, which have their own distinct reaction centres, named P680 and P700, respectively . These centres 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 into chlorophyll a and chlorophyll b . </P> <P> The function of the reaction center of chlorophyll is to absorb light energy and transfer it to other parts of the photosystem . The absorbed energy of the photon is transferred to an electron in a process called charge separation . The removal of the electron from the chlorophyll is an oxidation reaction . The chlorophyll donates the high energy electron to a series of molecular intermediates called an electron transport chain . The charged reaction center of chlorophyll (P680) is then reduced back to its ground state by accepting an electron stripped from water . The electron that reduces P680 ultimately comes from the oxidation of water into O and H through several intermediates . This reaction is how photosynthetic organisms such as plants produce O gas, and is the source for practically all the O in Earth's atmosphere . Photosystem I typically works in series with Photosystem II; thus the P700 of Photosystem I is usually reduced as it accepts the electron, via many intermediates in the thylakoid membrane, by electrons coming, 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 . </P>

Where will chlorophyll be found in the chloroplast