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Glucose 6-phosphatase
The enzyme glucose 6-phosphatase (EC 3.1.3.9, G6Pase; systematic name D-glucose-6-phosphate phosphohydrolase) catalyzes the hydrolysis of glucose 6-phosphate, resulting in the creation of a phosphate group and free glucose: : D-glucose 6-phosphate + H2O = D-glucose + phosphate Glucose is then exported from the cell via glucose transporter membrane proteins. This catalysis completes the final step in gluconeogenesis and therefore plays a key role in the homeostatic regulation of blood glucose levels. Glucose 6-phosphatase is a complex of multiple component proteins, including transporters for G6P, glucose, and phosphate. The main phosphatase function is performed by the glucose 6-phosphatase catalytic subunit. In humans, there are three isozymes of the catalytic subunit: glucose 6-phosphatase-α, encoded by G6PC; IGRP, encoded by G6PC2; and glucose 6-phosphatase-β, encoded by G6PC3. Glucose 6-phosphatase-α and glucose 6-phosphatase-β are both functional phosphohydrola ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutrophil
Neutrophils (also known as neutrocytes or heterophils) are the most abundant type of granulocytes and make up 40% to 70% of all white blood cells in humans. They form an essential part of the innate immune system, with their functions varying in different animals. They are formed from stem cells in the bone marrow and differentiated into subpopulations of neutrophil-killers and neutrophil-cagers. They are short-lived and highly mobile, as they can enter parts of tissue where other cells/molecules cannot. Neutrophils may be subdivided into segmented neutrophils and banded neutrophils (or bands). They form part of the polymorphonuclear cells family (PMNs) together with basophils and eosinophils. The name ''neutrophil'' derives from staining characteristics on hematoxylin and eosin ( H&E) histological or cytological preparations. Whereas basophilic white blood cells stain dark blue and eosinophilic white blood cells stain bright red, neutrophils stain a neutral pink ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperinsulinemic Clamp Technique
__NOTOC__ Glucose clamp technique is a method for quantifying insulin secretion and resistance. It is used to measure either how well an individual metabolizes glucose or how sensitive an individual is to insulin. Procedure Two types of clamp are quite commonly used. The hyperglycemic clamp, which requires maintaining a high blood sugar level by perfusion or infusion with glucose, is a way to quantify how fast beta-cells respond to glucose. The hyperinsulinemic clamp, which requires maintaining a high insulin level by perfusion or infusion with insulin, is a way to quantify how sensitive the tissue is to insulin. The hyperinsulinemic clamp is also called ''euglycemic clamp'', meaning a normal blood sugar level is maintained. Hyperglycemic clamp technique: The plasma glucose concentration is acutely raised to 125 mg/dl above basal levels by a continuous infusion of glucose. This hyperglycemic plateau is maintained by adjustment of a variable glucose infusion, based on the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vanadyl Sulfate
Vanadyl(IV) sulfate describes a collection of inorganic compounds of vanadium with the formula, VOSO4(H2O)x where 0 ≤ x ≤ 6. The pentahydrate is common. This hygroscopic blue solid is one of the most common sources of vanadium in the laboratory, reflecting its high stability. It features the vanadyl ion, VO2+, which has been called ''the'' "most stable diatomic ion". Vanadyl sulfate is an intermediate in the extraction of vanadium from petroleum residues, one commercial source of vanadium. Synthesis, structure, and reactions Vanadyl sulfate is most commonly obtained by reduction of vanadium pentoxide with sulfur dioxide: :V2O5 + 7 H2O + SO2 + H2SO4 → 2 (O)(H2O)4O4 From aqueous solution, the salt crystallizes as the pentahydrate, the fifth water is not bound to the metal in the solid. Viewed as a coordination complex, the ion is octahedral, with oxo, four equatorial water ligands, and a monodentate sulfate. The trihydrate has also been examined by crystallograp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexose Monophosphate Shunt
The pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt and the HMP Shunt) is a metabolic pathway parallel to glycolysis. It generates NADPH and pentoses (5-carbon sugars) as well as ribose 5-phosphate, a precursor for the synthesis of nucleotides. While the pentose phosphate pathway does involve oxidation of glucose, its primary role is anabolic rather than catabolic. The pathway is especially important in red blood cells (erythrocytes). There are two distinct phases in the pathway. The first is the oxidative phase, in which NADPH is generated, and the second is the non-oxidative synthesis of 5-carbon sugars. For most organisms, the pentose phosphate pathway takes place in the cytosol; in plants, most steps take place in plastids. Like glycolysis, the pentose phosphate pathway appears to have a very ancient evolutionary origin. The reactions of this pathway are mostly enzyme-catalyzed in modern cells, however, they also occu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycolysis
Glycolysis is the metabolic pathway that converts glucose () into pyruvate (). The free energy released in this process is used to form the high-energy molecules adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide (NADH). Glycolysis is a sequence of ten reactions catalyzed by enzymes. Glycolysis is a metabolic pathway that does not require oxygen (In anaerobic conditions pyruvate is converted to lactic acid). The wide occurrence of glycolysis in other species indicates that it is an ancient metabolic pathway. Indeed, the reactions that make up glycolysis and its parallel pathway, the pentose phosphate pathway, occur in the oxygen-free conditions of the Archean oceans, also in the absence of enzymes, catalyzed by metal. In most organisms, glycolysis occurs in the liquid part of cells, the cytosol. The most common type of glycolysis is the ''Embden–Meyerhof–Parnas (EMP) pathway'', which was discovered by Gustav Embden, Otto Meyerhof, and Jakub Ka ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycosylation
Glycosylation is the reaction in which a carbohydrate (or ' glycan'), i.e. a glycosyl donor, is attached to a hydroxyl or other functional group of another molecule (a glycosyl acceptor) in order to form a glycoconjugate. In biology (but not always in chemistry), glycosylation usually refers to an enzyme-catalysed reaction, whereas glycation (also 'non-enzymatic glycation' and 'non-enzymatic glycosylation') may refer to a non-enzymatic reaction (though in practice, 'glycation' often refers more specifically to Maillard-type reactions). Glycosylation is a form of co-translational and post-translational modification. Glycans serve a variety of structural and functional roles in membrane and secreted proteins. The majority of proteins synthesized in the rough endoplasmic reticulum undergo glycosylation. Glycosylation is also present in the cytoplasm and nucleus as the ''O''-GlcNAc modification. Aglycosylation is a feature of engineered antibodies to bypass glycosylation. Five cla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutropenia
Neutropenia is an abnormally low concentration of neutrophils (a type of white blood cell) in the blood. Neutrophils make up the majority of circulating white blood cells and serve as the primary defense against infections by destroying bacteria, bacterial fragments and immunoglobulin-bound viruses in the blood. People with neutropenia are more susceptible to bacterial infections and, without prompt medical attention, the condition may become life-threatening ( neutropenic sepsis). Neutropenia can be divided into congenital and acquired, with severe congenital neutropenia (SCN) and cyclic neutropenia (CyN) being autosomal dominant and mostly caused by heterozygous mutations in the ELANE gene ( neutrophil elastase). Neutropenia can be acute (temporary) or chronic (long lasting). The term is sometimes used interchangeably with "leukopenia" ("deficit in the number of white blood cells"). Decreased production of neutrophils is associated with deficiencies of vitamin B12 and fol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endoplasmic Reticulum
The endoplasmic reticulum (ER) is, in essence, the transportation system of the eukaryotic cell, and has many other important functions such as protein folding. It is a type of organelle made up of two subunits – rough endoplasmic reticulum (RER), and smooth endoplasmic reticulum (SER). The endoplasmic reticulum is found in most eukaryotic cells and forms an interconnected network of flattened, membrane-enclosed sacs known as cisternae (in the RER), and tubular structures in the SER. The membranes of the ER are continuous with the outer nuclear membrane. The endoplasmic reticulum is not found in red blood cells, or spermatozoa. The two types of ER share many of the same proteins and engage in certain common activities such as the synthesis of certain lipids and cholesterol. Different types of cells contain different ratios of the two types of ER depending on the activities of the cell. RER is found mainly toward the nucleus of cell and SER towards the cell membrane or plasma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucose-6-phosphate
Glucose 6-phosphate (G6P, sometimes called the Robison ester) is a glucose sugar phosphorylated at the hydroxy group on carbon 6. This dianion is very common in cells as the majority of glucose entering a cell will become phosphorylated in this way. Because of its prominent position in cellular chemistry, glucose 6-phosphate has many possible fates within the cell. It lies at the start of two major metabolic pathways: glycolysis and the pentose phosphate pathway. In addition to these two metabolic pathways, glucose 6-phosphate may also be converted to glycogen or starch for storage. This storage is in the liver and muscles in the form of glycogen for most multicellular animals, and in intracellular starch or glycogen granules for most other organisms. Production From glucose Within a cell, glucose 6-phosphate is produced by phosphorylation of glucose on the sixth carbon. This is catalyzed by the enzyme hexokinase in most cells, and, in higher animals, glucokinase in certain cell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutations
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosis, or meiosis or other types of damage to DNA (such as pyrimidine dimers caused by exposure to ultraviolet radiation), which then may undergo error-prone repair (especially microhomology-mediated end joining), cause an error during other forms of repair, or cause an error during replication ( translesion synthesis). Mutations may also result from insertion or deletion of segments of DNA due to mobile genetic elements. Mutations may or may not produce detectable changes in the observable characteristics (phenotype) of an organism. Mutations play a part in both normal and abnormal biological processes including: evolution, cancer, and the development of the immune system, including junctional diversity. Mutation is the ultimate so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hierarchy Of Glucose-6-phosphatase System Deficiency
A hierarchy (from Greek: , from , 'president of sacred rites') is an arrangement of items (objects, names, values, categories, etc.) that are represented as being "above", "below", or "at the same level as" one another. Hierarchy is an important concept in a wide variety of fields, such as architecture, philosophy, design, mathematics, computer science, organizational theory, systems theory, systematic biology, and the social sciences (especially political philosophy). A hierarchy can link entities either directly or indirectly, and either vertically or diagonally. The only direct links in a hierarchy, insofar as they are hierarchical, are to one's immediate superior or to one of one's subordinates, although a system that is largely hierarchical can also incorporate alternative hierarchies. Hierarchical links can extend "vertically" upwards or downwards via multiple links in the same direction, following a path. All parts of the hierarchy that are not linked vertically to one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
