General physiology; an outline of the science of life . Jlbstf ; „^-i^B»^?i» <• »-• Fig. 51.—An elongated pseudopodium of Lieberkuknia in which an infusorian (Colpidium colpoda)has become caught ; «, j, c, ?, e,f, various stages of digestion of the infusorian. undergo destruction. This indicates that very probably the nucleustakes an important share in the digestion of the as proteids are transformed by pepsin in an acid and by 154 GENERAL PHYSIOLOGY trypsin in an alkaline solution, so also the insoluble carbohydrates,such as starch, are changed into soluble forms both in i
General physiology; an outline of the science of life . Jlbstf ; „^-i^B»^?i» <• »-• Fig. 51.—An elongated pseudopodium of Lieberkuknia in which an infusorian (Colpidium colpoda)has become caught ; «, j, c, ?, e,f, various stages of digestion of the infusorian. undergo destruction. This indicates that very probably the nucleustakes an important share in the digestion of the as proteids are transformed by pepsin in an acid and by 154 GENERAL PHYSIOLOGY trypsin in an alkaline solution, so also the insoluble carbohydrates,such as starch, are changed into soluble forms both in intracellularand extracellular digestion by the action of certain enzymes. Ashas been seen, starch is a polysaccharid, which represents a com-bination of several sugar molecules in the anhydride form. By theaction of the enzyme, , the ptyalin of the saliva and the pancre-. Fig. 52.—Carchesium polypinum, scheme of the path taken by the ingested food in digestion andexpulsion of the excreta. The food enters through the pharynx and is transported downward(small circles), where it is stored in the concavity of the sausage-shaped nucleus (the latteris recognised by its containing darker bodies). It remains here for some time at rest (smallcrosses). Then it passes upward upon the other side (dots) and returns to the middle of thecell, where it undergoes dissolution. The excreta are removed to the outside, through theopening of the cell-mouth. The black line with arrows indicates the direction of the path.(After Greenwood.) atic juice in animals or the diastase in plants, the polymeric starchmolecule is split up through hydrolysis into simple sugarmolecules, maltose and dextrose, which are soluble in water. Inthe intracellular digestion of Infusoria, as M. Meissner (88) hasshown, starch -grains are slowly digested from the outside, so thatthey appear as if g
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Keywords: ., bookcentury1800, bookdecade1890, bookidgen, booksubjectphysiology
