Results 151 to 160 of about 15,848 (179)

Osmoregulatory Capacity of Contractile Vacuoles

Nature, 1948
THE view that the contractile vacuoles of Protozoa in many cases perform an osmoregulatory function has been supported by much evidence1 which need not be repeated here. Recent observations carried out on the freshwater peritrich ciliate Carchesium aselli have demonstrated the remarkably close regulation of body volume which is achieved in spite of ...
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Contractile Vacuole Complexes in Algae

1984
Contractile vacuoles are organelles which occur in many protists and some freshwater sponges. They are defined by their behaviour of slowly filling with fluid and periodically expelling this fluid from the cell (for review see Patterson 1980). Contractile vacuoles form one part of a more extensive organelle, the contractile vacuole complex.
D. J. Patterson, K. Hausmann
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The contractile vacuole and its membrane dynamics

BioEssays, 2000
The contractile vacuole (CV) is an osmoregulatory organelle whose mechanisms of function are poorly understood. Immunological studies in the last decade have demonstrated abundant proton-translocating V-type ATPases (V-ATPases) in its membrane that could provide the energy, from proton electrochemical gradients, for moving ions into the CV to be ...
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Contractile Vacuoles of Protozoa

1956
A contractile vacuole is a vesicle containing water and lying within the cytoplasm of the cell. It increases in volume, and finally discharges its contents to the outside. In many Protozoa there is a permanent position at which contractile vacuoles continually form, grow and discharge.
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Mechanism of the Diastole of Contractile Vacuoles

Nature, 1937
IT is still not known what causes the passage of fluid from the cytoplasm into the contractile vacuole of a protozoan. In a recently published paper1, Picken has claimed that the rate of this ” infiltration” of fluid into the vacuole will be proportional, among other things, to the difference between the hydrostatic pressure of the cytoplasm (which is ...
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The contractile vacuole of paramecium multimicronucleata

Journal of Morphology, 1935
AbstractEach contractile vacuole system of Paramecium multimicronucleata is made up of a number of components, some temporary and others permanent. The contracting vacuole with its membrane is a temporary structure as are the vesicles which fuse to form it. The vacuole discharges its contents to the exterior leaving a vestige closing the pore. The pore,
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The Physiology of Contractile Vacuoles

Journal of Experimental Biology, 1960
ABSTRACT The suctorian Discophrya collini (Root) has been subjected to D2O–H2O mixtures containing up to 99·7 % D2O. In 25 % D2O or over there is a rapid but temporary shrinkage of the body. This shrinkage is difficult to estimate owing to the wrinkling of the body surface, but amounts to at least 10% in the undiluted (99.7%) D2O. During
J. E. Padfield, J. A. Kitching, M. H. Rogers   +2 more
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The Contractile Vacuole in Amoeba proteus: Temperature Effects

The Journal of Protozoology, 1974
SYNOPSISThe influence of temperature on the various aspects of the contractile vacuole cycle of Amoeba proteus has been established. In the upper temperature range (20, 25 and 30 C) an increase in temperature results in shorter vacuolar cycles with greater systolic (final) volumes. The systole is rapid and always complete. At 35 C the vacuole shows the
Mukhtar Ahmad, Pierre Couillard
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ATP and the autonomy of the contractile vacuole in Amoeba proteus

Journal of Experimental Zoology, 1984
AbstractContractile vacuole function in amoebae treated with immobilizing (5 mM) and nonimmobilizing (0.125 mM) concentrations of ATP has been studied. In ATP‐immobilized amoebae, most vacuolar parameters are accelerated, especially the rate of output which passes from 30 to 70 μm3/sec. This favors the concept of an autonomous vacuole, fully functional
Pierre Couillard, F. Pothier, J. Forget
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The formation of contractile vacuoles in Amoeba proteus

Journal of Morphology, 1927
AbstractThe history of investigations on the contractile vacuole is reviewed briefly and brought up to date.The study of the contractile vacuole in Amoeba proteus is considered from standpoints of origin, structure, behavior, and function. The results are obtained from a prolonged study of normal organisms and from their reactions when introduced into ...
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