. Botany of the living plant. Botany; Plants. SYNTHESIS, STORAGE AND BREAKDOWN 115 expressed in terms of heat units, is indicated in the following equa- tion which sums up the process of photosynthesis. 6C02 + 6H20 + 674,000 calories = C6H1206 + 602 That is, the synthesis of a gramme-molecule (180 gm.) of sugar requires the equivalent of 674,000 calories of heat-energy. It will be seen from this equation that photosynthesis consists of the formation of sugar from carbon dioxide and water, energy being utilised and oxygen liberated. The green pigment of plants, Chlorophyll, is a key substance i
. Botany of the living plant. Botany; Plants. SYNTHESIS, STORAGE AND BREAKDOWN 115 expressed in terms of heat units, is indicated in the following equa- tion which sums up the process of photosynthesis. 6C02 + 6H20 + 674,000 calories = C6H1206 + 602 That is, the synthesis of a gramme-molecule (180 gm.) of sugar requires the equivalent of 674,000 calories of heat-energy. It will be seen from this equation that photosynthesis consists of the formation of sugar from carbon dioxide and water, energy being utilised and oxygen liberated. The green pigment of plants, Chlorophyll, is a key substance in photosynthesis. The pigment is located in special protoplasmic bodies, the Chloroplasts, which are restricted to those organs of the plant that are exposed to light: they are especially abundant in the mesophyll of the leaf, which is the chief organ of photosynthesis. Experiment proves that only those parts of the plant that contain chlorophyll can carry on photo- synthesis. To confirm this, varie- gated leaves may be used, and it can be shown that only the green parts of the leaf can conduct photosynthesis. In order to de- tect the occurrence of photosyn- thesis one method is to test for the presence of the end-products. Sugars themselves are not so easily detected as the higher carbo- „ /shows the inclui plastid has swollen in water. (After Sachs.) plants is very quickly formed from the initially-produced sugars. A plant with variegated leaves is exposed to sunlight for several hours, at the end of which time a leaf is to be detached, and the outlines of the yellow and green parts noted. The leaf is dipped in boiling water and then immersed in methylated spirit, which is heated over a water-. Fig. 76. A. Chloroplasts in cells of the leaf of Funaria, showing small starch-grains included in them. B shows stages of division of the chloroplasts. hydrate Starch, which in many ^J?,,*^^ starch"grains -after. Please note that these images are extracted from scanned
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Keywords: ., bookcentury1900, bookpublis, booksubjectbotany, booksubjectplants
