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Protoplasm
Protoplasm (; ) is the living part of a cell that is surrounded by a plasma membrane. It is a mixture of small molecules such as ions, monosaccharides, amino acid, and macromolecules such as proteins, polysaccharides, lipids, etc. In some definitions, it is a general term for the cytoplasm (e.g., Mohl, 1846), but for others, it also includes the nucleoplasm (e.g., Strasburger, 1882). For Sharp (1921), "According to the older usage the extra-nuclear portion of the protoplast 'the entire cell, excluding the cell wall''was called "protoplasm," but the nucleus also is composed of protoplasm, or living substance in its broader sense. The current consensus is to avoid this ambiguity by employing Strasburger's '(1882)''terms cytoplasm Albert_von_Kölliker.html"_;"title="'coined_by_Albert_von_Kölliker">Kölliker_(1863),_originally_as_synonym_for_protoplasm''and_nucleoplasm_([''term_coined_by_Edouard_Van_Beneden.html" ;"title="Albert von Kölliker">Kölliker (1863), originally as syno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urschleim
''Bathybius haeckelii'' was a substance that British biologist Thomas Henry Huxley discovered and initially believed to be a form of primordial matter, a source of all organic life. He later admitted his mistake when it proved to be just the product of an inorganic chemical process (precipitation). In 1868 Huxley studied an old sample of mud from the Atlantic seafloor taken in 1857. When he first examined it, he had found only protozoan cells and placed the sample into a jar of alcohol to preserve it. Now he noticed that the sample contained an albuminous slime that appeared to be criss-crossed with veins. Huxley thought he had discovered a new organic substance and named it ''Bathybius haeckelii'', in honor of German biologist Ernst Haeckel. Haeckel had theorized about ''Urschleim'' ("primordial slime"), a protoplasm from which all life had originated. Huxley thought ''Bathybius'' could be that protoplasm, a missing link (in modern terms) between inorganic matter and organic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amoeba
An amoeba (; less commonly spelled ameba or amœba; plural ''am(o)ebas'' or ''am(o)ebae'' ), often called an amoeboid, is a type of cell or unicellular organism with the ability to alter its shape, primarily by extending and retracting pseudopods. Amoebae do not form a single taxonomic group; instead, they are found in every major lineage of eukaryotic organisms. Amoeboid cells occur not only among the protozoa, but also in fungi, algae, and animals. Microbiologists often use the terms "amoeboid" and "amoeba" interchangeably for any organism that exhibits amoeboid movement. In older classification systems, most amoebae were placed in the class or subphylum Sarcodina, a grouping of single-celled organisms that possess pseudopods or move by protoplasmic flow. However, molecular phylogenetic studies have shown that Sarcodina is not a monophyletic group whose members share common descent. Consequently, amoeboid organisms are no longer classified together in one group.Jan Pawlows ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleoplasm
The nucleoplasm, also known as karyoplasm, is the type of protoplasm that makes up the cell nucleus, the most prominent organelle of the eukaryotic cell. It is enclosed by the nuclear envelope, also known as the nuclear membrane. The nucleoplasm resembles the cytoplasm of a eukaryotic cell in that it is a gel-like substance found within a membrane, although the nucleoplasm only fills out the space in the nucleus and has its own unique functions. The nucleoplasm suspends structures within the nucleus that are not membrane-bound and is responsible for maintaining the shape of the nucleus. The structures suspended in the nucleoplasm include chromosomes, various proteins, nuclear bodies, the nucleolus, nucleoporins, nucleotides, and nuclear speckles. The soluble, liquid portion of the nucleoplasm is called the karyolymph nucleosol, or nuclear hyaloplasm. History The existence of the nucleus, including the nucleoplasm, was first documented as early as 1682 by the Dutch microscopis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deutoplasm
The deutoplasm comprises the food particles stored in the cytoplasm of an ovum or a cell, as distinguished from protoplasm, the yolk substance. Generally, the deutoplasm accumulates about the nucleus and is heavier than the surrounding cytoplasm. In chicken egg Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especial ...s, the cytoplasm and deutoplasm are separate. References Cell biology {{developmental-biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Félix Dujardin
Félix Dujardin (5 April 1801 – 8 April 1860) was a French biologist born in Tours. He is remembered for his research on protozoans and other invertebrates. Biography In 1840 he was appointed professor of geology and mineralogy at the University of Toulouse, and during the following year was a professor of zoology and botany at Rennes. In regard to his educational background, Dujardin was largely self-taught, the son of a watchmaker. Dujardin worked with microscopic animal life, and in 1834 proposed that a new group of one-celled organisms be called Rhizopoda. He denied naturalist Christian Gottfried Ehrenberg's theory that microscopic organisms were "complete organisms" similar to higher animals, specifically noting that they had specialized structures unique to single-celled organisms, which meant that foraminifera he was studying was not, as his contemporaries believed it to be, a mollusk. In addition to his studies of microscopic life, he did extensive research on in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lorenz Oken
Lorenz Oken (1 August 1779 – 11 August 1851) was a German naturalist, botanist, biologist, and ornithologist. Oken was born Lorenz Okenfuss (german: Okenfuß) in Bohlsbach (now part of Offenburg), Ortenau, Baden, and studied natural history and medicine at the universities of Freiburg and Würzburg. He went on to the University of Göttingen, where he became a ''Privatdozent'' (unsalaried lecturer), and shortened his name to Oken. As Lorenz Oken, he published a small work entitled ''Grundriss der Naturphilosophie, der Theorie der Sinne, mit der darauf gegründeten Classification der Thiere'' (1802). This was the first of a series of works which established him as a leader of the movement of " Naturphilosophie" in Germany. In it he extended to physical science the philosophical principles which Immanuel Kant (1724–1804) had applied to epistemology and morality. Oken had been preceded in this by Johann Gottlieb Fichte (1762–1814), who, acknowledging that Kant had discover ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuole
A vacuole () is a membrane-bound organelle which is present in plant and fungal cells and some protist, animal, and bacterial cells. Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic molecules including enzymes in solution, though in certain cases they may contain solids which have been engulfed. Vacuoles are formed by the fusion of multiple membrane vesicles and are effectively just larger forms of these. The organelle has no basic shape or size; its structure varies according to the requirements of the cell. Discovery Contractile vacuoles ("stars") were first observed by Spallanzani (1776) in protozoa, although mistaken for respiratory organs. Dujardin (1841) named these "stars" as ''vacuoles''. In 1842, Schleiden applied the term for plant cells, to distinguish the structure with cell sap from the rest of the protoplasm. In 1885, de Vries named the vacuole membrane as tonoplast. Function The function and signifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyaloplasm
The cytosol, also known as cytoplasmic matrix or groundplasm, is one of the liquids found inside cells (intracellular fluid (ICF)). It is separated into compartments by membranes. For example, the mitochondrial matrix separates the mitochondrion into many compartments. In the eukaryotic cell, the cytosol is surrounded by the cell membrane and is part of the cytoplasm, which also comprises the mitochondria, plastids, and other organelles (but not their internal fluids and structures); the cell nucleus is separate. The cytosol is thus a liquid matrix around the organelles. In prokaryotes, most of the chemical reactions of metabolism take place in the cytosol, while a few take place in membranes or in the periplasmic space. In eukaryotes, while many metabolic pathways still occur in the cytosol, others take place within organelles. The cytosol is a complex mixture of substances dissolved in water. Although water forms the large majority of the cytosol, its structure and prop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytoplasm
In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The main components of the cytoplasm are cytosol (a gel-like substance), the organelles (the cell's internal sub-structures), and various cytoplasmic inclusions. The cytoplasm is about 80% water and is usually colorless. The submicroscopic ground cell substance or cytoplasmic matrix which remains after exclusion of the cell organelles and particles is groundplasm. It is the hyaloplasm of light microscopy, a highly complex, polyphasic system in which all resolvable cytoplasmic elements are suspended, including the larger organelles such as the ribosomes, mitochondria, the plant plastids, lipid droplets, and vacuoles. Most cellular activities take place within the cytoplasm, such as many metabolic pathways including glycolysis, and processe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma Membrane
The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment (the extracellular space). The cell membrane consists of a lipid bilayer, made up of two layers of phospholipids with cholesterols (a lipid component) interspersed between them, maintaining appropriate membrane fluidity at various temperatures. The membrane also contains membrane proteins, including integral proteins that span the membrane and serve as membrane transporters, and peripheral proteins that loosely attach to the outer (peripheral) side of the cell membrane, acting as enzymes to facilitate interaction with the cell's environment. Glycolipids embedded in the outer lipid layer serve a similar purpose. The cell membrane controls the movement of substances in and out of cells and organelles, being selectively permeable to ions and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytoplasm
In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The main components of the cytoplasm are cytosol (a gel-like substance), the organelles (the cell's internal sub-structures), and various cytoplasmic inclusions. The cytoplasm is about 80% water and is usually colorless. The submicroscopic ground cell substance or cytoplasmic matrix which remains after exclusion of the cell organelles and particles is groundplasm. It is the hyaloplasm of light microscopy, a highly complex, polyphasic system in which all resolvable cytoplasmic elements are suspended, including the larger organelles such as the ribosomes, mitochondria, the plant plastids, lipid droplets, and vacuoles. Most cellular activities take place within the cytoplasm, such as many metabolic pathways including glycolysis, and processe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoplast
Protoplast (), is a biological term coined by Hanstein in 1880 to refer to the entire cell, excluding the cell wall. Protoplasts can be generated by stripping the cell wall from plant, bacterial, or fungal cells by mechanical, chemical or enzymatic means. Protoplasts differ from spheroplasts in that their cell wall has been completely removed. Spheroplasts retain part of their cell wall. In the case of Gram-negative bacterial spheroplasts, for example, the peptidoglycan component of the cell wall has been removed but the outer membrane component has not. Enzymes for the preparation of protoplasts Cell walls are made of a variety of polysaccharides. Protoplasts can be made by degrading cell walls with a mixture of the appropriate polysaccharide-degrading enzymes: During and subsequent to digestion of the cell wall, the protoplast becomes very sensitive to osmotic stress. This means cell wall digestion and protoplast storage must be done in an isotonic solution to prevent r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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