Chlorophyll-containing, greenness

Economically more meaningful would be the ab initio-synthesis of complex natural compounds by plant cells from CO2 and light. For this purpose the chlorophyll containing green parts (chloroplasts) of the plants would be needed which are able to effect photosynthesis. Only laboratory results are available in this area. More advanced results about flavour generation in plant cell cultures are available for ... 

Plastids are any of a number of interrelated organelles occurring in the cytoplasm of plant cells in which starch, oil, protein, pigments, etc., are stored. The chlorophyll-containing chloroplasts, the site of photosynthesis, are referred to as green plastids. 

Shoulder at 505 nm. Cells are green (chlorophyll containing) and possess both stigma and paraflagellar body (as with all normal Euglena). 

The importance of the interaction with photons in the natural world can hardly be overstated. It forms the basis for photosynthesis converting carbon dioxide and water into more complex plant-associated structures. This is effectively accomplished employing chlorophyll as the catalytic site (this topic will be dealt with more fully later in the chapter). Chlorophyll contains a metal atom within a polymeric matrix, so it illustrates the importance of such metal-polymer combinations. T oday, with the rebirth of green materials and green chemistry use of clean fuel—namely, sunlight—is increasing in both interest and understanding. 

Figure 8.1 Chlorophyll is the green pigment that captures light energy used in photosynthesis. Chlorophyll reflects green light instead of absorbing it, which is why plants that contain chlorophyll appear green.

Mitochondria were first observed by R. Altmann in 1890. He named them bioblasts, because he speculated that they and chloroplasts (the green chlorophyll-containing organelles of plants) might be intracellular symbionts that arose from bacteria and algae, respectively. This idea lay in disrepute until the recent discovery of mitochondrial nucleic acids. 

Fignre 19.30. Stmctnre of a Light-Harvesting Complex. Eight polypeptides, each of which binds three chlorophyll % molecules (green) and a carotenoid molecule (red), surround a central cavity that contains the reaction center. 

Photosynthesis uses sunlight as the energy source conversion of CO2 and H2O into carbohydrates and O2 by chlorophyll-containing plants is tantamount to photolysis of H2O followed by reduction of CO2 by H2. This natural process can be modified so that some H2 is liberated, and certain blue-green algae are effective for this purpose. 

Chlorophyll, the major porphyrin in plants, is similar to heme, except that it is coordinated with magnesium rather than iron, and it contains different substituents on the rings, including a long-chain alcohol (phytol). As a result of these structural differences, chlorophyll is green. 

Intrinsic fluorescence is relatively rare in biological molecules. Most of the naturally occurring nucleic acids, carbohydrates and lipids show little or no useful fluorescence in the normal UV/visible region. In proteins, fluorescence can only be seen from tryptophan residues and, to a lesser extent, tyrosine side chains. This intrinsic protein fluorescence can be used in a number of practical applications. Typical Trp and protein emission spectra are shown in Figures 2.24 and 2.25. Some proteins contain intrinsically fluorescent prosthetic groups such as reduced pyridine nucleotides and flavoproteins, and the chlorophylls from green plants show a red fluorescence emission. 

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