How to use Vacuole in a sentence
The naked cells which have been alluded to live in water, and call therefore for no differentiation in connection with this necessity; but those which are surrounded by a cell-wall always develop within themselves a vacuole or cavity which occupies the greater part of their interior, and the hydrostatic pressure of whose contents keeps tha protoplasm in contact with the membrane, setting up a condition of turgidity.
Most plant cells have a single vacuole that takes up much of the cell.
Copepod with large oil vacuole, storing energy for the winter months.
Factors produced by mast cells also caused vacuole formation but not cell death.
The fixation made evident the cytoplasm that surrounds the great central vacuole.Advertisement
The vacuole may then become a secretory vesicle that moves to the plasma membrane, where the contents can be discharged from the cell.
They have the same functions as the contractile vacuole of freshwater Protozoa.
Middle Saccamoeba showing contractile vacuole (CV) distending the uroid, and the nucleus (N).
Ameba moving toward the bottom left, prominent contractile vacuole toward rear.
In these we have (1) the evaporation from the damp delicate cell-walls into the intercellular spaces; (2) the imbibition by the cell-wall of water from the vacuole; (3) osmotic action, consequent upon the subsequent increased concentration of the cell sap, drawing water from the wood cells or vessels which abut upon the leaf parenchyma.Advertisement
Eventually the protoplasm usually forms only a lining to the cell wall, and a large vacuole filled with cell sap occupies the centre.
There is no reason to doubt that this vacuole is a normal cell-constituent, for it has been described in parasites in quite normal surroundings and conditions.
Using LCMS techniques, we have already proven that chalcone release takes place in the parasite digestive vacuole.
Middle Saccamoeba showing contractile vacuole (CV) distending the uroid, and the nucleus (N ).
Young cells ar full of cytoplasm, old cells generally contain a large vacuole or vacuoles, containing cell-sap, and with only a thin, almost invisible layer of cytoplasm on their walls.Advertisement
The cells in which the fungoid organism is vigorously flourishing are exceedingly active, showing large size, brilliant nuclei, protoplasm and vacuole, all of which give signs of iptense metabolic activity.
In Gnetum Gnemon, as described by Lotsy, a mature embryo-sac contains in the upper part a large central vacuole and a peripheral layer of protoplasm, including several nuclei, which take the place of the archegonia of Ephedra; the lower part of the embryo-sac, separated from the upper by a constriction, is full of parenchyma.
In Polia the connective tissue enclosed in the external muscular layer is eminently vacuolar - all the intermediate stages between such cells in which the vacuole predominates and the nucleus is peripheral and those in which the granular protoplasm still entirely fills them being moreover present.
In other forms such as Elodea, Nitella, Chara, &c., where the cytoplasm is mainly restricted to the periphery of the sap vacuole and lining the cell wall, the streaming movement is exhibited in one direction only.
In the yeast cell the nucleus is represented by a homogenous granule, probably of a nucleolar nature, surrounded and perhaps to some extent impregnated by chromatin and closely connected with a vacuole which often has chromatin at its periphery, and contains one or more volutin granules which appear to consist of nucleic acid in combination with an unknown base.Advertisement