CHEMICAL AND PHYSIOLOGICAL STUDIES. 177 



e. GlUCOSides. The glucose formed by the action upon these bodies 

 of various enzymes is useful as circulating food-material. 



/. Protein reserve, such as g'luten, zein, and, at times, the 

 amido-acid asparagin, although the latter is usually more a form of 

 CiFCUlating than reserve food. 



The various processes, both physical and chemical, which take 

 place in a green plant, from the absorption of raw food-materials 

 to the manufacture, utilisation, and storing of elaborated food in 

 the leaves and other parts, may, for greater convenience of 

 reference, be put into tabular form as follovrs : — 



A. Absorption of Raw Materials by the Roots. 



Substances absorbed = a. Water. 



b. Salts in solution (chiefly salts of Ca, 

 Mg, K, andFc). 



B. Upward Conduction of Raw Sap by the Wood. 



Moving forces = c. Transpiration current. 



d. Root-pressure. 



C. Elaboration of Raw Sap in Leaves and other Green Parts. 



Processes involved = e. Intake of COj, H^O, and Oj ; outgo of 0^. 



f. Photosynthesis : CO2 and HoO being 



synthesised in the chloroplasts to 

 form (1) Formaldehyde; (ii. ) Sugar, 



g. Starch stored in the chloroplasts, and 



gradually transformed into sugar by 

 enzymes, and used for cellulose 

 formation and circulating food. 

 A. Formation of amido-oompounds, some 

 being used at once to form protoplasm. 



D. Translocation, Utilisation, and Storage of Elaborated 

 Compounds. 



Processes involved = i. The sugar and amido-compounds con- 

 ducted by means of phloem and osmosis 

 to tissues requiringelaborated food (cir- 

 culating carbohydrates and proteids). 



k. Manufacture of proteidS from sugar, 

 amido-compounds, and a sulphur- 

 compound, some being used at once, 

 and some stored. Manufacture of 

 wood and cellulose. 



I. Storage of surplus proteid and carbo- 

 hydrate in various tissues ; subse- 

 quent conversion of these by enzymes 

 into more assimilable food = digestion. 



Of the processes above noted, /, I, and k, are mainly anabolic, whilst 

 g and I are mainly katabolio ; wood and cellulose (k) are, however, 

 katabolio formations. 



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