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Absorption Of Water
In higher plants water and minerals are absorbed through root hairs which are in contact with soil water and from the root hairs zone a little the root tips. Active absorption Active absorption refers to the absorption of water by roots with the help of adenosine triphosphate, generated by the root respiration: as the root cells actively take part in the process, it is called active absorption. According to Jenner, active absorption takes place in low transpiring and well-watered plants, and 4% of total water absorption is carried out in this process. The active absorption is carried out by two theories; active osmotic water absorption and Active non-osmotic water absorption. In this process, energy is not required. Active absorption is important for the plants. Active osmotic water absorption The root cells behave as an ideal osmotic pressure system through which water moves up from the soil solution to the root xylem along an increasing gradient of D.P.D. (suction pressure, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenosine Triphosphate
Adenosine triphosphate (ATP) is an organic compound that provides energy to drive many processes in living cells, such as muscle contraction, nerve impulse propagation, condensate dissolution, and chemical synthesis. Found in all known forms of life, ATP is often referred to as the "molecular unit of currency" of intracellular energy transfer. When consumed in metabolic processes, it converts either to adenosine diphosphate (ADP) or to adenosine monophosphate (AMP). Other processes regenerate ATP. The human body recycles its own body weight equivalent in ATP each day. It is also a precursor to DNA and RNA, and is used as a coenzyme. From the perspective of biochemistry, ATP is classified as a nucleoside triphosphate, which indicates that it consists of three components: a nitrogenous base (adenine), the sugar ribose, and the Polyphosphate, triphosphate. Structure ATP consists of an adenine attached by the 9-nitrogen atom to the 1′ carbon atom of a sugar (ribose), which i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maintenance Respiration
Maintenance respiration (or maintenance energy) refers to metabolism occurring in an organism that is needed to maintain that organism in a healthy, living state. Maintenance respiration contrasts with growth respiration, which is responsible for the synthesis of new structures in growth, nutrient uptake, nitrogen (N) reduction and phloem loading, whereas maintenance respiration is associated with protein and membrane turnover and maintenance of ion concentrations and gradients. In plants Maintenance respiration in plants refers to the amount of cellular respiration, measured by the carbon dioxide (CO2) released or oxygen (O2) consumed, during the generation of usable energy (mainly ATP, NADPH, and NADH) and metabolic intermediates used for (i) resynthesis of compounds that undergo renewal (turnover) in the normal process of metabolism (examples are enzymatic proteins, ribonucleic acids, and membrane lipids); (ii) maintenance of chemical gradients of ions and metabolites across c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Absorption
Active may refer to: Music * ''Active'' (album), a 1992 album by Casiopea * Active Records, a record label Ships * ''Active'' (ship), several commercial ships by that name * HMS ''Active'', the name of various ships of the British Royal Navy * USCS ''Active'', a US Coast Survey ship in commission from 1852 to 1861 * USCGC ''Active'', the name of various ships of the US Coast Guard * USRC ''Active'', the name of various ships of the US Revenue Cutter Service * USS ''Active'', the name of various ships of the US Navy Computers and electronics * Active Enterprises, a defunct video game developer * Sky Active, the brand name for interactive features on Sky Digital available in the UK and Ireland * Active (software), software used for open publishing by Indymedia; see Independent Media Center Sciences * Thermodynamic activity, measure of an effective concentration of a species in a mixture. * Activation, in chemistry the process whereby something is prepared for a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xylem
Xylem is one of the two types of transport tissue in vascular plants, the other being phloem. The basic function of xylem is to transport water from roots to stems and leaves, but it also transports nutrients. The word ''xylem'' is derived from the Ancient Greek word (''xylon''), meaning "wood"; the best-known xylem tissue is wood, though it is found throughout a plant. The term was introduced by Carl Nägeli in 1858. Structure The most distinctive xylem cells are the long tracheary elements that transport water. Tracheids and vessel elements are distinguished by their shape; vessel elements are shorter, and are connected together into long tubes that are called ''vessels''. Xylem also contains two other type of cells: parenchyma and fibers. Xylem can be found: * in vascular bundles, present in non-woody plants and non-woody parts of woody plants * in secondary xylem, laid down by a meristem called the vascular cambium in woody plants * as part of a stelar arrangement n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endosmosis
Osmosis (, ) is the spontaneous net movement or diffusion of solvent molecules through a selectively-permeable membrane from a region of high water potential (region of lower solute concentration) to a region of low water potential (region of higher solute concentration), in the direction that tends to equalize the solute concentrations on the two sides. It may also be used to describe a physical process in which any solvent moves across a selectively permeable membrane (permeable to the solvent, but not the solute) separating two solutions of different concentrations. Osmosis can be made to do work. Osmotic pressure is defined as the external pressure required to be applied so that there is no net movement of solvent across the membrane. Osmotic pressure is a colligative property, meaning that the osmotic pressure depends on the molar concentration of the solute but not on its identity. Osmosis is a vital process in biological systems, as biological membranes are semipermeab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Root
In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the surface of the soil, but roots can also be aerial or aerating, that is, growing up above the ground or especially above water. Function The major functions of roots are absorption of water, plant nutrition and anchoring of the plant body to the ground. Anatomy Root morphology is divided into four zones: the root cap, the apical meristem, the elongation zone, and the hair. The root cap of new roots helps the root penetrate the soil. These root caps are sloughed off as the root goes deeper creating a slimy surface that provides lubrication. The apical meristem behind the root cap produces new root cells that elongate. Then, root hairs form that absorb water and mineral nutrients from the soil. The first root in seed producing plants is the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peter Atkins
Peter William Atkins (born 10 August 1940) is an English chemist and a Fellow of Lincoln College at the University of Oxford. He retired in 2007. He is a prolific writer of popular chemistry textbooks, including ''Physical Chemistry'', ''Inorganic Chemistry'', and ''Molecular Quantum Mechanics''. Atkins is also the author of a number of popular science books, including ''Atkins' Molecules'', ''Galileo's Finger: The Ten Great Ideas of Science'' and ''On Being''. Career Atkins left school (Dr Challoner's Grammar School, Amersham) at fifteen and took a job at Monsanto as a laboratory assistant. He studied for A-levels by himself and gained a place, following a last-minute interview, at the University of Leicester. Atkins studied chemistry there, obtaining a BSc degree in chemistry, and a PhD degree in 1964 for research into electron spin resonance spectroscopy, and other aspects of theoretical chemistry. Atkins then took a postdoctoral position at UCLA as a Harkness Fellow of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otto Renner
Otto Renner (25 April 1883 in Neu-Ulm – 8 July 1960) was a German plant geneticist. Following the work of Erwin Baur, Renner established the theory of maternal plastid inheritance as a widely accepted genetic theory. He studied botany under Karl von Goebel and Ludwig Radlkofer at the University of Munich, and with Wilhelm Pfeffer at the University of Leipzig. From 1913 to 1920 he served as an associate professor of plant physiology at Munich, and afterwards, succeeded Christian Ernst Stahl as chair of botany at the University of Jena, where he was also director of the botanical gardens. In 1946 he returned as a professor to the University of Munich. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kenneth V
Kenneth is an English given name and surname. The name is an Anglicised form of two entirely different Gaelic personal names: ''Cainnech'' and '' Cináed''. The modern Gaelic form of ''Cainnech'' is ''Coinneach''; the name was derived from a byname meaning "handsome", "comely". A short form of ''Kenneth'' is '' Ken''. Etymology The second part of the name ''Cinaed'' is derived either from the Celtic ''*aidhu'', meaning "fire", or else Brittonic ''jʉ:ð'' meaning "lord". People :''(see also Ken (name) and Kenny)'' Places In the United States: * Kenneth, Indiana * Kenneth, Minnesota * Kenneth City, Florida In Scotland: * Inch Kenneth, an island off the west coast of the Isle of Mull Other * " What's the Frequency, Kenneth?", a song by R.E.M. * Hurricane Kenneth * Cyclone Kenneth Intense Tropical Cyclone Kenneth was the strongest tropical cyclone to make landfall in Mozambique since modern records began. The cyclone also caused significant damage in the Comoro Islan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Physiology
Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. Closely related fields include plant morphology (structure of plants), plant ecology (interactions with the environment), phytochemistry (biochemistry of plants), cell biology, genetics, biophysics and molecular biology. Fundamental processes such as photosynthesis, respiration, plant nutrition, plant hormone functions, tropisms, nastic movements, photoperiodism, photomorphogenesis, circadian rhythms, environmental stress physiology, seed germination, dormancy and stomata function and transpiration, both parts of plant water relations, are studied by plant physiologists. Aims The field of plant physiology includes the study of all the internal activities of plants—those chemical and physical processes associated with life as they occur in plants. This includes study at many levels of scale of size and time. At the smallest scale are molecular interactions of photosynthesi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
