'Vacuole: Store House of Cell: Single membrane bound structure. membrane of vacuole is known as Tonoplast which is similar to cell membrane or plasma membrane chemically and structurally, Tonoplast is selectively permeable membrane which allows the entry and exit of certain inorganic and organic molecules. Cell sap or vacuolar sap: contain sugar,amino acids, organic acids, mineral water salts pigments, enzymes etc. vacuole present in all eukaryotic cells except mature Mammalian RBC,meristmatic cells of plans, prokaryotic cells. shapes: spherical sac like rounded, oval, elongated. position: in the cytoplasm of the cells. in mature plant cells mostly single Large prominent, permanent centrally located vacuole present.and occupy approx 90% volume of cell cytoplasm. primordial utricle: in mature plant cells vacuole is centrally located hence all other components of Cell pushed towards the boundary of Cell and appear as thin layer of cytoplasm known as primordial utricle. in animal cells there are many small temporary vacuoles which are scattered throughout the cell. Types of vacuole 1 Food vacuole: * Phagosome : undigested solid food containing vacuole. * Pinosome : undigested liquid food containing vacuole 2 Gas vacuole/ pseudo vacuole air or gas like oxygen, carbon dioxide, nitrogen gas containing vacuole, found in aquatic plants and animals and provide buoyancy/ floating ability to them. 3 contractile vacuole: present in some fresh water protozoan like amoeba and paramecium.helps in osmoregulation and excretion. Functions of Vacuoles: * storage of substances * Osmoregulation * Excretion * Elongation of plant cells * Provide Buoyancy * provide turgidity and turgor pressure to cells. * helps in opening and closing of stomatal pores. * storage of waste toxic metabolic byproducts of plants.'
Tags: food vacuole , Vacuole Structure and function , Store House of Cell , sap vacuole , contractile vacuole , primordial utricle
See also:
comments