Green plant, composition

Typically several different carotenoids occur in plant tissues containing this class of pigments. Carotenoids are accumulated in chloroplasts of all green plants as mixtures of a- and P-carotene, P-cryptoxanthin, lutein, zeaxanthin, violaxanthin, and neoxanthin. These pigments are found as complexes formed by noncovalent bonding with proteins. In green leaves, carotenoids are free, nonesterified, and their compositions depend on the plant and developmental conditions. In reproductive... 

The carbohydrates are substances made by green plants from carbon dioxide that they extract from the air and from water absorbed from the soil. The term carbohydrate is derived from the chemical formulas of the compounds, which can be written so as to express their composition in terms of atoms of carbon combined with molecules of water the formula for sucrose (table sugar), for example, is C12H22011f but it can also be written as C12(H20)ll, indicating that the molecule consists of 11 molecules of water... 

Table 1-4 compares the composition of a bacterium, of a green plant, and of an active animal tissue (rat liver). Although the solid matter of cells consists principally of C, H, O, N, S, and P, many other chemical elements are also present. Among the cations, Na+, K+, Ca2+, and Mg2+ are found in relatively large amounts. Tlius, the body of a 70 kg person contains 1050 g Ca (mostly in the bones), 245 g K, 105 g Na, and 35 g Mg. Iron (3 g), zinc (2.3 g), and rubidium (1.2 g) are the next most abundant. Of these iron and zinc are essential to life but rubidium is probably not. It is evidently taken up by the body together with potassium. 

This composite satellite image displays areas on the surface of the Earth where chlorophyll-bearing plants are located. Chlorophyll, which is one of nature s most important biomolecules, is a member of a class of compounds called porphyrins. This Glass also includes hemoglobin and cytochrome c, which is discussed in Feature 19-1. Many analytical techniques have been used to measure the chemical and physical properties of chlorophyll to explore Its role in photosynthesis. The redox titration of chlorophyll with other standard redox couples reveals the oxidation/ reduction properties of the molecule that help explain the photophysics of the complex process that green plants use to oxidize water to molecular oxygen. 

Coles, L., Hay, J.B. Gray, G.M. (1970) Factors Affecting the Glycosphingolipid Composition of Murine Tissues , Journal of Lipid Research, 11,158-63 Colvin, J.R. (1961) Synthesis of Cellulose from Ethanol-Soluble Precursors in Green Plants , Canadian Journal of Biochemistry and Physiology, 39, 1921-6 Cook, G.M.W. Stoddart, R.W. (1973) Surface Carbohydrates of the Eukaryotic Cell, pp. 346. Academic Press, London New York... 

We found that only in cases where the preexisting (in ImL) PSII unit content (activity/g fr w)-irrespective of unit size-, and the H2G-MV rate reach those of fully green plants, further changes in thylakoid composition cease in CL. Moreover, in plants preexposed to ImL with very long dark intervals (where the cytf/Chl or cytf/PSII is in excess of that in green controls) transfer to CL stimulates PSII unit formation in excess of that in controls (so that the desired PSII/cytf ratio may be attained)... 

The carbon-autotrophic green plant is the primary producer of carbohydrates on the earth and uses carbohydrates extensively as storage and cell-wall substances (starch, cellulose, etc). The nitrogen-hetero-trophic animal usually consumes a rather protein-rich diet and uses proteins as supportive materials The approximate chemical composition of the human body is shown in Table 2. Most of the mass of bacteria (see Escherichia coli) is made up by proteins, which may account for 70 % of the dry weight. Numerically,... 

Storage Polysaccharides. Starch and Starch Derivatives. Amylose and amlyopectin are the major components of starch granules found in food reserves of all green plants. Commercial starch is obtained from sources such as com, sorghum, rice, wheat, and potatoes. The compositions of the amylose and amy-lopectin vary with source. 

The fact that chlorophyll is essential for photosynthesis has been known for a long time, but it was not until the work of Willstatter and co-workers 17) in the early 1900 s that the chemical nature of chlorophyll was established. These investigators showed that the chlorophyll in green plants was made up of two components, chlorophyll-a and chlorophyll-b, with the following composition ... 

Nevertheless, the interpretation of differences between the two batches could be very difficult. How should a change in the pH value (e.g., from 7.9 to 8.2), or in the plant available fractions of nutrients in relation to their total content be interpreted A more readily applied result could be obtained from bioassays, since any decrease of the germination rate of the seed or any reduction of plant growth (production of green plant biomass) could easily be declared as a loss of compost quality, independent of the chemical composition. 

---