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Metabolic Flexibility
Metabolic flexibility is the capacity to alter metabolism in response to exercise or available fuel (especially fats and carbohydrates). Metabolic inflexibility was first described as the ability to generate energy through either aerobic or anaerobic respiration or as the inability of muscle to increase glucose oxidation in response to insulin. An organism can also be said to have metabolic flexibility if it is capable of metabolizing either carbohydrate or fat efficiency, depending on availability of those fuels. With aging there is a decrease in metabolic flexibility due to a decline in pyruvate dehydrogenase activity which results in pyruvate increasingly being anaerobically converted to lactate rather than aerobically converted to acetyl-CoA. Similarly, a virus-induced cytokine storm A cytokine storm, also called hypercytokinemia, is a physiological reaction in humans and other animals in which the innate immune system causes an uncontrolled and excessive release of pro- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metabolism
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the conversion of food to building blocks for proteins, lipids, nucleic acids, and some carbohydrates; and the elimination of metabolic wastes. These enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their structures, and respond to their environments. The word metabolism can also refer to the sum of all chemical reactions that occur in living organisms, including digestion and the transportation of substances into and between different cells, in which case the above described set of reactions within the cells is called intermediary (or intermediate) metabolism. Metabolic reactions may be categorized as '' catabolic'' – the ''breaking down'' of compounds (for example, of glucose to pyruvate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactic Acid
Lactic acid is an organic acid. It has a molecular formula . It is white in the solid state and it is miscible with water. When in the dissolved state, it forms a colorless solution. Production includes both artificial synthesis as well as natural sources. Lactic acid is an alpha-hydroxy acid (AHA) due to the presence of a hydroxyl group adjacent to the carboxyl group. It is used as a synthetic intermediate in many organic synthesis industries and in various biochemical industries. The conjugate base of lactic acid is called lactate (or the lactate anion). The name of the derived acyl group is lactoyl. In solution, it can ionize by loss of a proton to produce the lactate ion . Compared to acetic acid, its p''K'' is 1 unit less, meaning lactic acid is ten times more acidic than acetic acid. This higher acidity is the consequence of the intramolecular hydrogen bonding between the α-hydroxyl and the carboxylate group. Lactic acid is chiral, consisting of two enantiomers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulin Resistance
Insulin resistance (IR) is a pathological condition in which cells fail to respond normally to the hormone insulin. Insulin is a hormone that facilitates the transport of glucose from blood into cells, thereby reducing blood glucose (blood sugar). Insulin is released by the pancreas in response to carbohydrates consumed in the diet. In states of insulin resistance, the same amount of insulin does not have the same effect on glucose transport and blood sugar levels. There are many causes of insulin resistance and the underlying process is still not completely understood, but sulfate depletion may be the important factor. Risk factors for insulin resistance include obesity, sedentary lifestyle, family history of diabetes, various health conditions, and certain medications. Insulin resistance is considered a component of the metabolic syndrome. There are multiple ways to measure insulin resistance such as fasting insulin levels or glucose tolerance tests, but these are not often use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Hindawi Academic Journals
This is a list of academic journal An academic journal or scholarly journal is a periodical publication in which scholarship relating to a particular academic discipline is published. Academic journals serve as permanent and transparent forums for the presentation, scrutiny, and ...s published by Hindawi. A B C D E G H I J L M N O P Q R S T U V W References {{Reflist External linksList of journals published by Hindawi * Hindawi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyruvate Dehydrogenase Complex
Pyruvate dehydrogenase complex (PDC) is a complex of three enzymes that converts pyruvate into acetyl-CoA by a process called pyruvate decarboxylation. Acetyl-CoA may then be used in the citric acid cycle to carry out cellular respiration, and this complex links the glycolysis metabolic pathway to the citric acid cycle. Pyruvate decarboxylation is also known as the "pyruvate dehydrogenase reaction" because it also involves the oxidation of pyruvate. This multi-enzyme complex is related structurally and functionally to the oxoglutarate dehydrogenase and branched-chain oxo-acid dehydrogenase multi-enzyme complexes. Reaction The reaction catalysed by pyruvate dehydrogenase complex is: Structure Pyruvate dehydrogenase (E1) The E1 subunit, called the pyruvate dehydrogenase subunit, has a structure that consists of two chains (an “ɑ” and “ꞵ” chain). A magnesium ion forms a 4-coordinate complex with three, polar amino acid residues (Asp, Asn, and Tyr) located on t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytokine Storm
A cytokine storm, also called hypercytokinemia, is a physiological reaction in humans and other animals in which the innate immune system causes an uncontrolled and excessive release of pro-inflammatory signaling molecules called cytokines. Normally, cytokines are part of the body's immune response to infection, but their sudden release in large quantities can cause multisystem organ failure and death. Cytokine storms can be caused by a number of infectious and non-infectious etiologies, especially viral respiratory infections such as H1N1 influenza, H5N1 influenza, SARS-CoV-1, and SARS-CoV-2, Influenza B, Parainfluenza virus, and Ebola. Other causative agents include the Epstein-Barr virus, cytomegalovirus, group A streptococcus, and non-infectious conditions such as graft-versus-host disease. The viruses can invade lung epithelial cells and alveolar macrophages to produce viral nucleic acid, which stimulates the infected cells to release cytokines and chemokines, activatin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUBMB Life
''IUBMB Life'' is a peer-reviewed scientific journal of developmental biology that was established in 1999. It is one of four official journals of the IUBMB. The journal is published monthly by John Wiley & Sons. According to the ''Journal Citation Reports'', the journal has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as ... of 3.885, ranking it 147th out of 297 journals in the category "Biochemistry and Molecular Biology" and 121st out of 195 journals in the category "Cell Biology". Aims and Scope IUBMB Life is the flagship journal of the International Union of Biochemistry and Molecular Biology and is devoted to the rapid publication of the most novel and significant original research articles, reviews, and hypotheses in the broadly defined fields of bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetyl-CoA
Acetyl-CoA (acetyl coenzyme A) is a molecule that participates in many biochemical reactions in protein, carbohydrate and lipid metabolism. Its main function is to deliver the acetyl group to the citric acid cycle (Krebs cycle) to be oxidized for energy production. Coenzyme A (CoASH or CoA) consists of a β-mercaptoethylamine group linked to the vitamin pantothenic acid (B5) through an amide linkage and 3'-phosphorylated ADP. The acetyl group (indicated in blue in the structural diagram on the right) of acetyl-CoA is linked to the sulfhydryl substituent of the β-mercaptoethylamine group. This thioester linkage is a "high energy" bond, which is particularly reactive. Hydrolysis of the thioester bond is exergonic (−31.5 kJ/mol). CoA is acetylated to acetyl-CoA by the breakdown of carbohydrates through glycolysis and by the breakdown of fatty acids through β-oxidation. Acetyl-CoA then enters the citric acid cycle, where the acetyl group is oxidized to carbon dioxide and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyruvate
Pyruvic acid (CH3COCOOH) is the simplest of the alpha-keto acids, with a carboxylic acid and a ketone functional group. Pyruvate, the conjugate base, CH3COCOO−, is an intermediate in several metabolic pathways throughout the cell. Pyruvic acid can be made from glucose through glycolysis, converted back to carbohydrates (such as glucose) via gluconeogenesis, or to fatty acids through a reaction with acetyl-CoA. It can also be used to construct the amino acid alanine and can be converted into ethanol or lactic acid via fermentation. Pyruvic acid supplies energy to cells through the citric acid cycle (also known as the Krebs cycle) when oxygen is present (aerobic respiration), and alternatively ferments to produce lactate when oxygen is lacking. Chemistry In 1834, Théophile-Jules Pelouze distilled tartaric acid and isolated glutaric acid and another unknown organic acid. Jöns Jacob Berzelius characterized this other acid the following year and named pyruvic acid bec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exercise
Exercise is a body activity that enhances or maintains physical fitness and overall health and wellness. It is performed for various reasons, to aid growth and improve strength, develop muscles and the cardiovascular system, hone athletic skills, weight loss or maintenance, improve health, or simply for enjoyment. Many individuals choose to exercise outdoors where they can congregate in groups, socialize, and improve well-being as well as mental health. In terms of health benefits, the amount of recommended exercise depends upon the goal, the type of exercise, and the age of the person. Even doing a small amount of exercise is healthier than doing none. Classification Physical exercises are generally grouped into three types, depending on the overall effect they have on the human body: * Aerobic exercise is any physical activity that uses large muscle groups and causes the body to use more oxygen than it would while resting. The goal of aerobic exercise is to inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyruvate Dehydrogenase
Pyruvate dehydrogenase is an enzyme that catalyzes the reaction of pyruvate and a lipoamide to give the acetylated dihydrolipoamide and carbon dioxide. The conversion requires the coenzyme thiamine pyrophosphate. Pyruvate dehydrogenase is usually encountered as a component, referred to as E1, of the pyruvate dehydrogenase complex (PDC). PDC consists of other enzymes, referred to as E2 and E3. Collectively E1-E3 transform pyruvate, NAD+, coenzyme A into acetyl-CoA, CO2, and NADH. The conversion is crucial because acetyl-CoA may then be used in the citric acid cycle to carry out cellular respiration. To distinguish between this enzyme and the PDC, it is systematically called pyruvate dehydrogenase (acetyl-transferring). Mechanism The thiamine pyrophosphate (TPP) converts to an ylide by deprotonation. The ylide attack the ketone group of pyruvate. The resulting adduct decarboxylates. The resulting 1,3-dipole reductively acetylates lipoamide-E2. In terms of details, bioch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diabetes (journal)
''Diabetes'' is a monthly peer-reviewed medical journal published since 1952 by the American Diabetes Association. It covers research about the physiology and pathophysiology of diabetes mellitus including any aspect of laboratory, animal or human research. Emphasis is on investigative reports focusing on areas such as the pathogenesis of diabetes and its complications, normal and pathologic pancreatic islet function and intermediary metabolism, pharmacological mechanisms of drug and hormone action, and biochemical and molecular aspects of normal and abnormal biological processes. Diabetes also publishes abstracts presented at the ADA's annual meeting, Scientific Sessions, as a supplement. According to the ''Journal Citation Reports'', the journal has a 2021 impact factor of 9.337, and 5 years impact factor of 10.509 ranking it 8th out of 240 journals in the category "Endocrinology, Diabetes & Metabolism". See also * American Diabetes Association * ''Diabetes Care ''Diabetes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
