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Ernest Overton
Charles Ernest Overton (1865–1933) was a British and Swedish physiologist and biologist, now regarded as a pioneer of the theory of the cell membrane. In the last years of the 19th century Overton did experimental work, allowing the distinction to be drawn between the cell wall of plants and their cytoplasmic membrane. He studied the permeability of a range of biological materials to around 500 chemical compounds. In 1900, Overton proposed a biomembrane model "Overton Biomembrane Model" which stated that biomembranes are made up of lipids. He gave this statement on the basis of observation of transport of lipid soluble substances across the biomembranes. He came to Lund University Lund University () is a Public university, public research university in Sweden and one of Northern Europe's oldest universities. The university is located in the city of Lund in the Swedish province of Scania. The university was officially foun ... in Sweden as a professor, and married Louise ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Membrane
The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell 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 a cell, being selectively permeable to ions and organic mole ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Wall
A cell wall is a structural layer that surrounds some Cell type, cell types, found immediately outside the cell membrane. It can be tough, flexible, and sometimes rigid. Primarily, it provides the cell with structural support, shape, protection, and functions as a selective barrier. Another vital role of the cell wall is to help the cell withstand osmotic pressure and mechanical stress. While absent in many eukaryotes, including animals, cell walls are prevalent in other organisms such as fungi, algae and plants, and are commonly found in most Prokaryote, prokaryotes, with the exception of Mollicutes, mollicute bacteria. The composition of cell walls varies across taxonomic groups, species, cell type, and the cell cycle. In Embryophyte, land plants, the primary cell wall comprises Polysaccharide, polysaccharides like cellulose, hemicelluloses, and pectin. Often, other Polymer, polymers such as lignin, suberin or cutin are anchored to or embedded in plant cell walls. Algae exhibit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytoplasmic Membrane
The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the cytoplasm, interior of a Cell (biology), cell from the extracellular space, 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 Membrane fluidity, 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 membrane transport, controls the movement of substances in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semipermeable Membrane
Semipermeable membrane is a type of synthetic or biologic, polymeric membrane that allows certain molecules or ions to pass through it by osmosis. The rate of passage depends on the pressure, concentration, and temperature of the molecules or solutes on either side, as well as the permeability of the membrane to each solute. Depending on the membrane and the solute, permeability may depend on solute size, solubility, properties, or chemistry. How the membrane is constructed to be selective in its permeability will determine the rate and the permeability. Many natural and synthetic materials which are rather thick are also semipermeable. One example of this is the thin film on the inside of an egg. Biological membranes are selectively permeable, with the passage of molecules controlled by facilitated diffusion, passive transport or active transport regulated by proteins embedded in the membrane. Biological membranes Phospholipid bilayer A phospholipid bilayer is an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lund University
Lund University () is a Public university, public research university in Sweden and one of Northern Europe's oldest universities. The university is located in the city of Lund in the Swedish province of Scania. The university was officially founded in 1666 on the location of the old ''studium generale'' next to Lund Cathedral. Lund University has nine Faculty (division), faculties, with additional campuses in the cities of Malmö and Helsingborg, with around 47,000 students in 241 different programmes and 1,450 freestanding courses. The university has 560 partner universities in approximately 70 countries. It belongs to the League of European Research Universities as well as the global Universitas 21 network. Among those associated with the university are five Nobel Prize winners, a Fields Medal winner, prime ministers and business leaders. Two major facilities for materials research have been recent strategic priorities in Lund: MAX IV, a synchrotron radiation laboratory – in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louise Petrén-Overton
Hedvig Louise Beata Petrén-Overton (August 12, 1880 – January 14, 1977) was a Swedish mathematician, the first woman in Sweden with a doctorate in mathematics. Early life and education Louise Petrén was one of twelve children of the vicar of Halmstad. Her father had earned a doctorate in mathematics in 1850, and her great-uncle had been a professor of mathematics at Lund University. One of her brothers was physician and researcher Karl Anders Petrén. With two older sisters doing the housework, she was left free to concentrate on her studies. As a child, ill with scarlet fever, she told her family that she would not go to heaven unless she could bring her mathematics books there. She earned an education certificate through private tutoring in 1899, and earned a bachelor's degree at Lund University in 1902, as one of roughly a dozen women at the university and the only one in the sciences. She earned a licenciate in 1910 and defended her doctorate at Lund in 1911, with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meyer-Overton Hypothesis
Minimum alveolar concentration or MAC is the concentration, often expressed as a percentage by volume, of a vapour in the alveoli of the lungs that is needed to prevent movement (motor response) in 50% of subjects in response to surgical (pain) stimulus. MAC is used to compare the strengths, or potency, of anaesthetic vapours. The concept of MAC was first introduced in 1965. MAC actually is a ''median'' value, not a minimum as term implies. The original paper proposed MAC as the ''minimal'' alveolar concentration, which was shortly thereafter revised to ''minimum'' alveolar concentration. A lower MAC value represents a more potent volatile anesthetic. Other uses of MAC include MAC-BAR (1.7–2.0 MAC), which is the concentration required to block autonomic reflexes to nociceptive stimuli, and MAC-awake (0.3–0.5 MAC), the concentration required to block voluntary reflexes and control perceptive awareness. Formal definition The MAC is the concentration of the vapour (measured a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1865 Births
Events January * January 4 – The New York Stock Exchange opens its first permanent headquarters at 10-12 Broad near Wall Street, in New York City. * January 13 – American Civil War: Second Battle of Fort Fisher – Union forces launch a major amphibious assault against the last seaport held by the Confederates, Fort Fisher, North Carolina. * January 15 – American Civil War: Union forces capture Fort Fisher. * January 31 ** The Thirteenth Amendment to the United States Constitution (conditional prohibition of slavery and involuntary servitude) passes narrowly, in the House of Representatives. ** American Civil War: Confederate General Robert E. Lee becomes general-in-chief. February * February 3 – American Civil War: Hampton Roads Conference: Union and Confederate leaders discuss peace terms. * February 6 – The municipal administration of Finland is established. * February 8 & March 8 – Gregor Mendel reads his paper on '' E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1933 Deaths
Events January * January 11 – Australian aviator Sir Charles Kingsford Smith makes the first commercial flight between Australia and New Zealand. * January 17 – The United States Congress votes in favour of Philippines independence, against the wishes of U.S. President Herbert Hoover. * January 28 – "Pakistan Declaration": Choudhry Rahmat Ali publishes (in Cambridge, UK) a pamphlet entitled ''Now or Never; Are We to Live or Perish Forever?'', in which he calls for the creation of a Muslim state in northwest India that he calls "Pakistan, Pakstan"; this influences the Pakistan Movement. * January 30 ** Nazi Party leader Adolf Hitler is appointed Chancellor of Germany (German Reich), Chancellor of Germany by President of Germany Paul von Hindenburg. ** Édouard Daladier forms a government in France in succession to Joseph Paul-Boncour. He is succeeded on October 26 by Albert Sarraut and on November 26 by Camille Chautemps. February * February 1 – Adolf Hitle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
19th-century British Biologists
The 19th century began on 1 January 1801 (represented by the Roman numerals MDCCCI), and ended on 31 December 1900 (MCM). It was the 9th century of the 2nd millennium. It was characterized by vast social upheaval. Slavery was abolished in much of Europe and the Americas. The First Industrial Revolution, though it began in the late 18th century, expanded beyond its British homeland for the first time during the 19th century, particularly remaking the economies and societies of the Low Countries, France, the Rhineland, Northern Italy, and the Northeastern United States. A few decades later, the Second Industrial Revolution led to ever more massive urbanization and much higher levels of productivity, profit, and prosperity, a pattern that continued into the 20th century. The Catholic Church, in response to the growing influence and power of modernism, secularism and materialism, formed the First Vatican Council in the late 19th century to deal with such problems and confirm ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Physiologists
British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories and Crown Dependencies. * British national identity, the characteristics of British people and culture * British English, the English language as spoken and written in United Kingdom of Great Britain and Northern Ireland and, more broadly, throughout the British Isles * Celtic Britons, an ancient ethno-linguistic group * Brittonic languages, a branch of the Insular Celtic language family (formerly called British) ** Common Brittonic, an ancient language Other uses *People or things associated with: ** Great Britain, an island ** British Isles, an island group ** United Kingdom, a sovereign state ** British Empire, a historical global colonial empire ** Kingdom of Great Britain (1707–1800) ** United Kingdom of Great Britain and Ireland (1801–1922) * British Raj, colonial India under the British Empire * British Hong Kong, colonial Ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
