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Aerobe
An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment. The ability to exhibit aerobic respiration may yield benefits to the aerobic organism, as aerobic respiration yields more energy than anaerobic respiration. Energy production of the cell involves the synthesis of Adenosine triphosphate, ATP by an enzyme called ATP synthase. In aerobic respiration, ATP synthase is coupled with an electron transport chain in which oxygen acts as a terminal electron acceptor. In July 2020, Marine biology, marine biologists reported that aerobic microorganisms (mainly), in "Suspended animation, quasi-suspended animation", were found in Sediment, organically poor sediments, up to 101.5 million years old, 250 feet below the Seabed, seafloor in the South Pacific Gyre (SPG) ("the deadest spot in the ocean"), and could be the List of longest-living organisms, longest-living life forms ever found. Types *Obligate aerobes need oxygen to grow. In a process kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaerobic Organism
An anaerobic organism or anaerobe is any organism that does not require oxygen, molecular oxygen for growth. It may react negatively or even die if free oxygen is present. In contrast, an aerobic organism (aerobe) is an organism that requires an oxygenated environment. Anaerobes may be unicellular (e.g. protozoans, bacteria) or multicellular. Most fungi are obligate aerobes, requiring oxygen to survive. However, some species, such as the Chytridiomycota that reside in the rumen of cattle, are obligate anaerobes; for these species, anaerobic respiration is used because oxygen will disrupt their metabolism or kill them. The sea floor is possibly one of the largest accumulation of anaerobic organisms on Earth, where microbes are primarily concentrated around Hydrothermal_vent, hydrothermal vents. These microbes produce energy in absence of sunlight or oxygen through a process called chemosynthesis, whereby inorganic compounds such as hydrogen gas, hydrogen sulfide or ferrous ions are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obligate Aerobe
An obligate aerobe is an organism that requires oxygen to grow. Through cellular respiration, these organisms use oxygen to metabolise substances, like sugars or fats, to obtain energy. In this type of respiration, oxygen serves as the terminal electron acceptor for the electron transport chain. Aerobic respiration has the advantage of yielding more energy ( adenosine triphosphate or ATP) than fermentation or anaerobic respiration, but obligate aerobes are subject to high levels of oxidative stress."Obligate aerobe - definition from Biology-Online.org." ''Biology Online.'' Biology-Online, n.d. Web. 12 Dec 2009. Examples Among organisms, almost all animals, most fungi, and several bacteria are obligate aerobes. Examples of obligately aerobic bacteria include ''Mycobacterium tuberculosis'' (acid-fast), ''Bacillus'' (Gram-positive), and ''Nocardia asteroides'' (Gram-positive). With the exception of the yeasts, most fungi are obligate aerobes. Also, almost all algae are obliga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Facultative Anaerobic Organism
A facultative anaerobic organism is an organism that makes ATP by aerobic respiration if oxygen is present, but is capable of switching to fermentation if oxygen is absent. Some examples of facultatively anaerobic bacteria are '' Staphylococcus'' spp., ''Escherichia coli'', ''Salmonella'', '' Listeria'' spp., '' Shewanella oneidensis'' and '' Yersinia pestis''. Certain eukaryotes are also facultative anaerobes, including pupfish, fungi such as ''Saccharomyces cerevisiae'' and many aquatic invertebrates such as nereid polychaetes. It has been observed that in mutants of '' Salmonella typhimurium'' that underwent mutations to be either obligate aerobes or anaerobes, there were varying levels of chromatin-remodeling proteins. The obligate aerobes were later found to have a defective DNA gyrase subunit A gene ('' gyrA''), while obligate anaerobes were defective in topoisomerase I (''topI''). This indicates that topoisomerase I and its associated relaxation of chromosomal DNA is r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerotolerant
Aerotolerant anaerobes use fermentation to produce Adenosine triphosphate, ATP. They do not use oxygen, but they can protect themselves from reactive oxygen molecules. In contrast, obligate anaerobes can be harmed by reactive oxygen molecules. There are three categories of anaerobes. Where obligate aerobes require oxygen to grow, obligate anaerobes are damaged by oxygen, aerotolerant organisms cannot use oxygen but tolerate its presence, and facultative anaerobes use oxygen if it is present but can grow without it. Most aerotolerant anaerobes have superoxide dismutase and (non-catalase) peroxidase but do not have catalase. More specifically, they may use a NADH oxidase/NADH peroxidase (NOX/NPR) system or a glutathione peroxidase system. An example of an aerotolerant anaerobe is ''Cutibacterium acnes''. References [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microaerophile
A microaerophile is a microorganism that requires environments containing lower levels of dioxygen than that are present in the atmosphere (i.e. < 21% O2; typically 2–10% O2) for optimal growth. A more restrictive interpretation requires the microorganism to be obligate in this requirement. Many microaerophiles are also capnophiles, requiring an elevated concentration of (e.g. 10% CO2 in the case of '' Campylobacter'' ). The original ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pasteur Effect
The Pasteur effect describes how available oxygen inhibits ethanol fermentation, driving yeast to switch toward aerobic respiration for increased generation of the energy carrier adenosine triphosphate (ATP). More generally, in the medical literature, the Pasteur effect refers to how the presence of oxygen causes in a decrease in the cellular rate of glycolysis and suppression of lactate accumulation. The effect occurs in animal tissues, as well as in microorganisms belonging to the fungal kingdom. Discovery In 1857, microbiologist Louis Pasteur showed that aeration of yeasted broth causes cell growth to increase while the fermentation rate decreases, based on lowered ethanol production. Explanation Yeast fungi, being facultative anaerobes, can either produce energy through ethanol fermentation or aerobic respiration. When the O2 concentration is low, the two pyruvate molecules formed through glycolysis are each fermented into ethanol and carbon dioxide. While only 2 ATP ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen
Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), nonmetal, and a potent oxidizing agent that readily forms oxides with most elements as well as with other chemical compound, compounds. Oxygen is abundance of elements in Earth's crust, the most abundant element in Earth's crust, making up almost half of the Earth's crust in the form of various oxides such as water, carbon dioxide, iron oxides and silicates.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. It is abundance of chemical elements, the third-most abundant element in the universe after hydrogen and helium. At standard temperature and pressure, two oxygen atoms will chemical bond, bind covalent bond, covalently to form dioxygen, a colorless and odorless diatomic gas with the chemical formula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucose
Glucose is a sugar with the Chemical formula#Molecular formula, molecular formula , which is often abbreviated as Glc. It is overall the most abundant monosaccharide, a subcategory of carbohydrates. It is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using energy from sunlight. It is used by plants to make cellulose, the most abundant carbohydrate in the world, for use in cell walls, and by all living Organism, organisms to make adenosine triphosphate (ATP), which is used by the cell as energy. In energy metabolism, glucose is the most important source of energy in all organisms. Glucose for metabolism is stored as a polymer, in plants mainly as amylose and amylopectin, and in animals as glycogen. Glucose circulates in the blood of animals as blood sugar. The naturally occurring form is -glucose, while its Stereoisomerism, stereoisomer L-glucose, -glucose is produced synthetically in comparatively small amounts and is less biologicall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerobic Metabolism
Cellular respiration is the process of oxidizing biological fuels using an inorganic electron acceptor, such as oxygen, to drive production of adenosine triphosphate (ATP), which stores chemical energy in a biologically accessible form. Cellular respiration may be described as a set of metabolic reactions and processes that take place in the cells of organisms to transfer chemical energy from nutrients to ATP, with the flow of electrons to an electron acceptor, and then release waste products. If the electron acceptor is oxygen, the process is more specifically known as aerobic cellular respiration. If the electron acceptor is a molecule other than oxygen, this is anaerobic cellular respiration. Fermentation, which is also an anaerobic process, is not respiration, as no external electron acceptor is involved. The reactions involved in respiration are catabolic reactions, which break large molecules into smaller ones, producing large amounts of energy (ATP). Respiration i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaerobic
Anaerobic means "living, active, occurring, or existing in the absence of free oxygen", as opposed to aerobic which means "living, active, or occurring only in the presence of oxygen." Anaerobic may also refer to: *Adhesive#Anaerobic, Anaerobic adhesive, a bonding agent that does not cure in the presence of air *Anaerobic respiration, respiration in the absence of oxygen, using some other molecule as the final electron acceptor **Anaerobic organism, any organism whose redox metabolism does not depend on free oxygen **Anammox, anaerobic ammonium oxidation, a globally important microbial process of the nitrogen cycle **Anaerobic filter, an anaerobic digester with a tank containing a filter medium where anaerobic microbes can establish themselves **Anaerobic digestion, the use of anaerobic bacteria to break down waste, with biogas as a byproduct ***Anaerobic clarigester, an anaerobic digester that treats dilute biodegradable feedstocks and allows different retention times for solids an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monosaccharide
Monosaccharides (from Greek '' monos'': single, '' sacchar'': sugar), also called simple sugars, are the simplest forms of sugar and the most basic units (monomers) from which all carbohydrates are built. Chemically, monosaccharides are polyhydroxy aldehydes with the formula or polyhydroxy ketones with the formula with three or more carbon atoms. They are usually colorless, water- soluble, and crystalline organic solids. Contrary to their name (sugars), only some monosaccharides have a sweet taste. Most monosaccharides have the formula (CH2O)''x'' (though not all molecules with this formula are monosaccharides). Examples of monosaccharides include glucose (dextrose), fructose (levulose), and galactose. Monosaccharides are the building blocks of disaccharides (such as sucrose, lactose and maltose) and polysaccharides (such as cellulose and starch). The table sugar used in everyday vernacular is itself a disaccharide sucrose comprising one molecule of each of the two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Krebs Cycle
The citric acid cycle—also known as the Krebs cycle, Szent–Györgyi–Krebs cycle, or TCA cycle (tricarboxylic acid cycle)—is a series of biochemical reactions that release the energy stored in nutrients through acetyl-CoA oxidation. The energy released is available in the form of ATP. The Krebs cycle is used by organisms that generate energy via respiration, either anaerobically or aerobically (organisms that ferment use different pathways). In addition, the cycle provides precursors of certain amino acids, as well as the reducing agent NADH, which are used in other reactions. Its central importance to many biochemical pathways suggests that it was one of the earliest metabolism components. Even though it is branded as a "cycle", it is not necessary for metabolites to follow a specific route; at least three alternative pathways of the citric acid cycle are recognized. Its name is derived from the citric acid (a tricarboxylic acid, often called citrate, as the ioni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
