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Encyclopedia > Vacuole
Schematic of typical animal cell, showing subcellular components: (1) nucleolus (2) nucleus (3) ribosome (4) vesicle (5) rough endoplasmic reticulum (ER) (6) Golgi apparatus (7) Cytoskeleton (8) smooth ER (9) mitochondria (10) vacuole (11) cytoplasm (12) lysosome (13) centrioles
Schematic of typical animal cell, showing subcellular components: (1) nucleolus (2) nucleus (3) ribosome (4) vesicle (5) rough endoplasmic reticulum (ER) (6) Golgi apparatus (7) Cytoskeleton (8) smooth ER (9) mitochondria (10) vacuole (11) cytoplasm (12) lysosome (13) centrioles

Vacuoles are found in the cytoplasm of most plant cells and some animal cells. Vacuoles are membrane-bound compartments within some eukaryotic cells that can serve a variety of secretory, excretory, and storage functions. Vacuoles and their contents are considered to be distinct from the cytoplasm, and are classified as ergastic according to some authors.[1] Vacuoles are especially conspicuous in most plant cells. Image File history File links Biological_cell. ... Image File history File links Biological_cell. ... The nucleolus is contained within the cell nucleus. ... HeLa cells stained for DNA with the Blue Hoechst dye. ... Figure 1: Ribosome structure indicating small subunit (A) and large subunit (B). ... In cell biology, a vesicle is a relatively small and enclosed compartment, separated from the cytosol by at least one lipid bilayer. ... The endoplasmic reticulum or ER is an organelle found in all eukaryotic cells that is an interconnected network of tubules, vesicles and cisternae that is responsible for several specialized functions: Protein translation, folding, and transport of proteins to be used in the cell membrane (e. ... Micrograph of Golgi apparatus, visible as a stack of semicircular black rings near the bottom. ... The eukaryotic cytoskeleton. ... The endoplasmic reticulum or ER (endoplasmic means within the cytoplasm, reticulum means little net) is an organelle found in all eukaryotic cells. ... Electron micrograph of a mitochondrion showing its mitochondrial matrix and membranes In cell biology, a mitochondrion (plural mitochondria) is a membrane-enclosed organelle that is found in most eukaryotic cells. ... Schematic showing the cytoplasm, with major components of a typical animal cell. ... Various organelles labeled. ... A centriole showing the nine triplets of microtubules. ... Look up cell membrane in Wiktionary, the free dictionary. ... Kingdoms Animalia - Animals Fungi Plantae - Plants Chromalveolata Protista Alternative phylogeny Unikonta Opisthokonta Metazoa Choanozoa Eumycota Amoebozoa Bikonta Apusozoa Cabozoa Rhizaria Excavata Corticata Archaeplastida Chromalveolata Animals, plants, fungi, and protists are eukaryotes (IPA: ), organisms whose cells are organized into complex structures by internal membranes and a cytoskeleton. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the... Schematic showing the cytoplasm, with major components of a typical animal cell. ... Ergastic substances are non-protoplasm materials found in cells. ... Plant cell structure Plant cells are eukaryotic cells that differ in several key respects from the cells of other eukaryotic organisms. ...

Contents

Functions

In general, vacuole functions include also

  • Removing unwanted structural debris
  • Isolating materials that might be harmful or a threat to the cell
  • Containing waste products
  • Maintaining internal hydrostatic pressure or turgor within the cell
  • Maintaining an acidic internal pH
  • Containing small molecules
  • Exporting unwanted substances from the cell

Vacuoles also play a major role in autophagy, maintaining a balance between biogenesis (production) and degradation (or turnover), of many substances and cell structures. They also aid in destruction of invading bacteria or of misfolded proteins that have begun to build up within the cell. The vacuole is a major part in the plant and animal cell. Hydrostatic pressure is the pressure exerted by a fluid due to its weight. ... Turgor (also called turgor pressure or osmotic pressure) is the pressure that can build in a space that is enclosed by a membrane that is permeable to a solvent of a solution such as water but not to the solutes of the soluton. ... For alternative meanings see acid (disambiguation). ... Autophagy is also a synonym for self-cannibalism Autophagy, or ocytosis, is a process of sequestering organelles and long-lived proteins in a double-membrane vesicle inside the cell, where the contents are subsequently delivered to the lysosome for degradation. ... Biogenesis is the process of lifeforms producing other lifeforms, e. ... Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ...


Protists

Some protists and macrophages use food vacuoles as a stage in phagocytosis—the intake of large molecules, particles, or even other cells, by the cell for digestion. They are also called "storage sacs." Typical phyla Chromalveolata Chromista Heterokontophyta Haptophyta Cryptophyta (cryptomonads) Alveolata Dinoflagellata Apicomplexa Ciliophora (ciliates) Cabozoa Excavata Euglenozoa Percolozoa Metamonada Rhizaria Radiolaria Foraminifera Cercozoa Archaeplastida (in part) Rhodophyta (red algae) Glaucophyta (basal archaeplastids) Amoebozoa Choanozoa Many others; classification varies Protists (IPA: (RP); (GenAm)), Greek protiston -a meaning the (most) first of all... A macrophage of a mouse stretching its arms to engulf two particles, possibly pathogens Macrophages (Greek: big eaters, from makros large + phagein eat) are cells within the tissues that originate from specific white blood cells called monocytes. ... Steps of a macrophage ingesting a pathogen: a. ... For the industrial process, see anaerobic digestion. ...


A contractile vacuole is used to pump excess water out of the cell to reduce osmotic pressure and keep the cell from bursting, which is referred to as cytolysis or osmotic lysis. Figure 1: A paramecium. ... Turgor (also called turgor pressure or osmotic pressure) is the pressure that can build in a space that is enclosed by a membrane that is permeable to a solvent of a solution such as water but not to the solutes of the soluton. ... Cytolysis is the lysis, or death, of cells due to the rupture of the cell membrane. ...


Budding yeast

In budding yeast cells, vacuoles act as storage compartments of amino acids and detoxification compartments. Under conditions of starvation, proteins are degraded in vacuoles; this is called autophagy. First, cytoplasms, mitochondrion, and small organelles are covered with multiplex plasma membranes called autophagosomes. Next, the autophagosomes fuse the vacuoles. Finally, the cytoplasms and the organelles are degraded. Typical divisions Ascomycota (sac fungi) Saccharomycotina (true yeasts) Taphrinomycotina Schizosaccharomycetes (fission yeasts) Basidiomycota (club fungi) Urediniomycetes Sporidiales Yeasts are a growth form of eukaryotic micro organisms classified in the kingdom Fungi, with about 1,500 species described;[1] they dominate fungal diversity in the oceans. ... In chemistry, an amino acid is any molecule that contains both amino and carboxylic acid functional groups. ... Detox, short for detoxification, in general is the removal of toxic substances from the body. ... Schematic showing the cytoplasm, with major components of a typical animal cell. ... Electron micrograph of a mitochondrion showing its mitochondrial matrix and membranes In cell biology, a mitochondrion (plural mitochondria) is a membrane-enclosed organelle that is found in most eukaryotic cells. ... In cell biology, an organelle is a specialized subunit within a cell that has a specific function, and is separately enclosed within its own lipid membrane. ...


In a vacuole of budding yeast, black particles sometimes appear, called a dancing body. The dancing body moves actively in the vacuole and appears and disappears within 10 minutes to several hours. In previous research, it was suggested but not proven that the main component of the dancing body is polyphosphate acid. But the main component has been determined to be crystallized sodium polyphosphate and its function has been studied. It is thought that its function is to supply and store phosphates in budding yeast cells. Polyphosphates are phosphate polymers linked between hydroxyl groups and hydrogen atoms. ...


Plants

Most mature plant cells have one or several vacuoles that typically occupy more than 30% of the cell's volume, and that can occupy as much as 90% of the volume for certain cell types and conditions.[2] A vacuole is surrounded by a membrane called the tonoplast. Plant cell structure Plant cells are eukaryotic cells that differ in several key respects from the cells of other eukaryotic organisms. ...


This vacuole houses large amounts of a liquid called cell sap, composed of water, enzymes, inorganic ions (like K+ and Cl-), salts (such as calcium), and other substances, including toxic byproducts removed from the cytosol to avoid interference with metabolism. Toxins present in the vacuole may also help to protect some plants from predators. Transport of protons from cytosol to vacuole aids in keeping cytoplasmic pH stable, while making the vacuolar interior more acidic, allowing degradative enzymes to act. Although having a large central vacuole is the most common case, the size and number of vacuoles may vary in different tissues and stages of development. Cells of the vascular cambium, for example, have many small vacuoles in winter, and one large one in summer. Cell sap is a dilute fluid that is found in the large central vacuole of many plant cells. ... Neuraminidase ribbon diagram An enzyme (in Greek en = in and zyme = blend) is a protein, or protein complex, that catalyzes a chemical reaction and also controls the 3D orientation of the catalyzed substrates. ... For other uses, see Calcium (disambiguation). ... Structure of the coenzyme adenosine triphosphate, a central intermediate in energy metabolism. ... For other uses, see Proton (disambiguation). ... For other uses, see PH (disambiguation). ... The vascular cambium is a lateral meristem: The vascular cambium is the source of both the secondary xylem (inwards) and the secondary phloem (outwards), and hence is located between these tissues in the stem. ...


Aside from storage, the main role of the central vacuole is to maintain turgor pressure against the cell wall. Proteins found in the tonoplast control the flow of water into and out of the vacuole through active transport, pumping potassium (K+) ions into and out of the vacuolar interior. Due to osmosis, water will diffuse into the vacuole, placing pressure on the cell wall. If water loss leads to a significant decline in turgor pressure, the cell will plasmolyse. Turgor pressure exerted by vacuoles is also helpful for cellular elongation: as the cell wall is partially degraded by the action of auxins, the less rigid wall is expanded by the pressure coming from within the vacuole. Vacuoles can help some plant cells to reach considerable size. Another function of a central vacuole is that it pushes all contents of the cell's cytoplasm against the cellular membrane, and thus keeps the chloroplasts closer to light. Turgor (also called turgor pressure or osmotic pressure) is the pressure that can build in a space that is enclosed by a membrane that is permeable to a solvent of a solution such as water but not to the solutes of the soluton. ... Plant cells separated by transparent cell walls. ... Sodium-Potassium pump, an example of Primary active transport Active transport (sometimes called active uptake) is an energy-requiring process that moves material across a cell membrane and up the concentration gradient. ... General Name, symbol, number potassium, K, 19 Chemical series alkali metals Group, period, block 1, 4, s Appearance silvery white Standard atomic weight 39. ... This article is about the electrically charged particle. ... Osmosis is the spontaneous net movement of water across a semipermeable membrane from a region of low solute concentration to a solution with a high solute concentration, down a solute concentration gradient. ... Look up cell in Wiktionary, the free dictionary. ... Plant cell under different enviroments Before plasmolysis. ... Auxins are a group of plant growth substances (often called phytohormones or plant hormones), the most common example being indoleacetic acid (IAA), responsible for raising the pH around cells, making the cell wall less rigid and allowing elongation. ... Chloroplasts are organelles found in plant cells and eukaryotic algae which conduct photosynthesis. ...


The vacuole also stores the pigments in flowers and fruits. Natural Ultramarine pigment in powdered form. ... For other uses, see Flower (disambiguation). ... For other uses, see Fruit (disambiguation). ...


Animals

Vacuoles in animals are a part of the processes of exocytosis and endocytosis. Exocytosis is the extrusion process of proteins from the Golgi apparatus initially enter secretory granules, where processing of prohormones to the mature hormones occurs before exocytosis, and also allows the animal cell to rid waste products. Endocytosis is the reverse of exocytosis. There are various types. Phagocytosis ("cell eating") is the process by which bacteria, dead tissue, or other bits of material visible under the microscope are engulfed by cells. The material makes contact with the cell membrane, which then invaginates. The invagination is pinched off, leaving the engulfed material in the membrane-enclosed vacuole and the cell membrane intact. Pinocytosis ("cell drinking") is essentially the same process, the difference being that the substances ingested are in solution and not visible under the microscope [3] Neuron A (transmitting) to neuron B (receiving) 1. ... Endocytosis (IPA: ) is a process whereby cells absorb material (molecules such as proteins) from the outside by engulfing it with their cell membrane. ... Micrograph of Golgi apparatus, visible as a stack of semicircular black rings near the bottom. ... Steps of a macrophage ingesting a pathogen: a. ... Pinocytosis or cell drinking is one of three forms of endocytosis, a cellular process that is used to take up smaller particles in cell by splitting in small particles , and forms vesicles which then merge with lysosomes to hydrolyze (hydrolytic enyzmes) to break down the particles. ...


Hydropic (vacuolar) changes are of importance of identifying various pathologies, such as the reversible cell swelling in renal tubules caused by hypoperfusion of the kidneys during open heart surgery.


References

  1. ^ Esau, K. (1965). Plant Anatomy, 2nd Edition. John Wiley & Sons. 767 pp.
  2. ^ Alberts, Bruce, Johnson, Alexander, Lewis, Julian, Raff, Martin, Roberts, Keith, and Walter, Peter (2002). Molecular Biology of the Cell (Fourth Edition), (Garland Science, New York), p. 740.
  3. ^ William F. Ganong, MD (2003). "REVIEW OF MEDICAL PHYSIOLOGY - 21st Ed.". 
  • (2003) Lange Medical Books/McGraw-Hill, Medical Publishing Division, New York
In cell biology, an organelle is a specialized subunit within a cell that has a specific function, and is separately enclosed within its own lipid membrane. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the... In spermatozoa of many animals, the acrosome is an organelle that develops over the anterior half of the spermatozoons head. ... Plant cells separated by transparent cell walls. ... Look up cell membrane in Wiktionary, the free dictionary. ... A centriole showing the nine triplets of microtubules. ... Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. ... Not to be confused with Psyllium. ... For the insect anatomical structure, see Antenna (biology). ... In cell biology, the centrosome is the main microtubule organizing center (MTOC) of the animal cell as well as a regulator of cell-cycle progression. ... Schematic showing the cytoplasm, with major components of a typical animal cell. ... The endoplasmic reticulum or ER is an organelle found in all eukaryotic cells that is an interconnected network of tubules, vesicles and cisternae that is responsible for several specialized functions: Protein translation, folding, and transport of proteins to be used in the cell membrane (e. ... In biology an endosome is a membrane-bound compartment inside cells. ... Micrograph of Golgi apparatus, visible as a stack of semicircular black rings near the bottom. ... Various organelles labeled. ... In a biological cell, a melanosome is an organelle containing melanin, the most common light-absorbing pigment found in the animal kingdom. ... Electron micrograph of a mitochondrion showing its mitochondrial matrix and membranes In cell biology, a mitochondrion (plural mitochondria) is a membrane-enclosed organelle that is found in most eukaryotic cells. ... A diagram of the structure of a Myofybril Myofibrils (obsolete term: sarcostyles) are cylindrical organelles, found within muscle cells. ... HeLa cells stained for DNA with the Blue Hoechst dye. ... The nucleolus is contained within the cell nucleus. ... Parenthesomes are found in basidiomycete fungus. ... Basic structure of a peroxisome Peroxisomes are ubiquitous organelles in eukaryotes that participate in the metabolism of fatty acids and other metabolites. ... Plant cells with visible chloroplasts. ... Figure 1: Ribosome structure indicating small subunit (A) and large subunit (B). ... In cell biology, a vesicle is a relatively small and enclosed compartment, separated from the cytosol by at least one lipid bilayer. ...

  Results from FactBites:
 
Vacuole Summary (1625 words)
Vacuoles and their contents are considered to be distinct from the cytoplasm, and are classified as ergastic according to some authors (Esau, 1965).
Another function of a central vacuole is that it pushes all contents of the cell's cytoplasm against the cellular membrane, and thus keeps the chloroplasts closer to light.
In budding yeast cells, vacuoles are the storage compartments of amino acids and the detoxification compartment, which are described in previous topics.
Periodic tension development in the membrane of the in vitro contractile vacuole of Paramecium multimicronucleatum: ... (558 words)
The contractile vacuole of the freshwater protozoan Paramecium
to the increased membrane tension of the in vivo contractile vacuole that
vitro contractile vacuole corresponded to the fluid-filling phase of the in
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