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Ketosis
Ketosis is a metabolic state characterized by elevated levels of ketone bodies in the blood or urine. Physiological ketosis is a normal response to low glucose availability. In physiological ketosis, ketones in the blood are elevated above baseline levels, but the body's acid–base homeostasis is maintained. This contrasts with ketoacidosis, an uncontrolled production of ketones that occurs in pathologic states and causes a metabolic acidosis, which is a medical emergency. Ketoacidosis is most commonly the result of complete insulin deficiency in type 1 diabetes or late-stage type 2 diabetes. Ketone levels can be measured in blood, urine or breath and are generally between 0.5 and 3.0 millimolar (mM) in physiological ketosis, while ketoacidosis may cause blood concentrations greater than 10 mM. Trace levels of ketones are always present in the blood and increase when blood glucose reserves are low and the liver shifts from primarily metabolizing carbohydrates to metabolizi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ketoacidosis
Ketoacidosis is a metabolic state caused by uncontrolled production of ketone bodies that cause a metabolic acidosis. While ketosis refers to any elevation of blood ketones, ketoacidosis is a specific pathologic condition that results in changes in blood pH and requires medical attention. The most common cause of ketoacidosis is diabetic ketoacidosis but it can also be caused by alcohol, medications, toxins, and rarely, starvation. Signs and symptoms The symptoms of ketoacidosis are variable depending on the underlying cause. The most common symptoms include nausea, vomiting, abdominal pain, and weakness. Breath may also develop the smell of acetone as it is a volatile ketone that can be exhaled. Rapid deep breathing, or Kussmaul breathing, may be present to compensate for the metabolic acidosis. Altered mental status is more common in diabetic than alcoholic ketoacidosis. Causes Ketoacidosis is caused by the uncontrolled production of ketone bodies. Usually the production of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ketone Bodies
Ketone bodies are water-soluble molecules or compounds that contain the ketone groups produced from fatty acids by the liver ( ketogenesis). Ketone bodies are readily transported into tissues outside the liver, where they are converted into acetyl-CoA (acetyl-Coenzyme A)which then enters the citric acid cycle (Krebs cycle) and is oxidized for energy.Silva, B., Mantha, O. L., Schor, J., Pascual, A., Plaçais, P. Y., Pavlowsky, A., & Preat, T. (2022). Glia fuel neurons with locally synthesized ketone bodies to sustain memory under starvation. Nature Metabolism, 4(2), 213–224. https://doi.org/10.1038/s42255-022-00528-6 These liver-derived ketone groups include acetoacetic acid (acetoacetate), beta-hydroxybutyrate, and acetone, a spontaneous breakdown product of acetoacetate (see graphic). Ketone bodies are produced by the liver during periods of caloric restriction of various scenarios: low food intake (fasting), carbohydrate restrictive diets, starvation, prolonged intense e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetoacetate
Acetoacetic acid ( IUPAC name: 3-oxobutanoic acid, also known as acetonecarboxylic acid or diacetic acid) is the organic compound with the formula CHCOCHCOOH. It is the simplest beta-keto acid, and like other members of this class, it is unstable. The methyl and ethyl esters, which are quite stable, are produced on a large scale industrially as precursors to dyes. Acetoacetic acid is a weak acid. Biochemistry Under typical physiological conditions, acetoacetic acid exists as its conjugate base, acetoacetate: : Unbound acetoacetate is primarily produced by liver mitochondria from its thioester with coenzyme A (CoA): : The acetoacetyl-CoA itself is formed by three routes: *3-hydroxy-3-methylglutaryl CoA releases acetyl CoA and acetoacetate: *: *Acetoacetyl-CoA can come from beta oxidation of butyryl-CoA: *: *Condensation of pair of acetyl CoA molecules as catalyzed by thiolase. *: In mammals, acetoacetate produced in the liver (along with the other two " ketone bodies") is r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ketogenesis
Ketogenesis is the biochemical process through which organisms produce ketone bodies by breaking down fatty acids and ketogenic amino acids. The process supplies energy to certain organs, particularly the brain, heart and skeletal muscle, under specific scenarios including fasting, caloric restriction, sleep, or others. (In rare metabolic diseases, insufficient gluconeogenesis can cause excessive ketogenesis and hypoglycemia, which may lead to the life-threatening condition known as non-diabetic ketoacidosis.) Ketone bodies are not obligately produced from fatty acids; rather a meaningful amount of them is synthesized only in a situation of carbohydrate and protein insufficiency, where only fatty acids are readily available as fuel for their production. Recent evidence suggests that glial cells are ketogenic, supplying neurons with locally synthesized ketone bodies to sustain cognitive processes. Production Ketone bodies are produced mainly in the mitochondria of liver cell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ketogenic Diet
The ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet, low-carbohydrate dietary therapy that in conventional medicine is used mainly to treat hard-to-control (refractory) epilepsy in children. The diet forces the body to burn fats rather than carbohydrates. Normally, carbohydrates in food are converted into glucose, which is then transported around the body and is important in Brain metabolism, fueling brain function. However, if only a little carbohydrate remains in the diet, the liver converts triacylglycerol, fat into fatty acids and ketone bodies, the latter passing into the brain and replacing glucose as an energy source. An elevated level of ketone bodies in the blood (a state called ketosis) eventually lowers the frequency of epileptic seizures. Around half of children and young people with epilepsy who have tried some form of this diet saw the number of seizures drop by at least half, and the effect persists after discontinuing the diet. Some eviden ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycogen
Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals, fungi, and bacteria. It is the main storage form of glucose in the human body. Glycogen functions as one of three regularly used forms of energy reserves, creatine phosphate being for very short-term, glycogen being for short-term and the triglyceride stores in adipose tissue (i.e., body fat) being for long-term storage. Protein, broken down into amino acids, is seldom used as a main energy source except during starvation and glycolytic crisis ''(see bioenergetic systems)''. In humans, glycogen is made and stored primarily in the cells of the liver and skeletal muscle. In the liver, glycogen can make up 5–6% of the organ's fresh weight: the liver of an adult, weighing 1.5 kg, can store roughly 100–120 grams of glycogen. In skeletal muscle, glycogen is found in a low concentration (1–2% of the muscle mass): the skeletal muscle of an adult weighing 70 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fatty Acid Oxidation
In biochemistry and metabolism, beta oxidation (also β-oxidation) is the catabolic process by which fatty acid molecules are broken down in the cytosol in prokaryotes and in the mitochondria in eukaryotes to generate acetyl-CoA. Acetyl-CoA enters the citric acid cycle, generating NADH and FADH2, which are electron carriers used in the electron transport chain. It is named as such because the beta carbon of the fatty acid chain undergoes oxidation and is converted to a carbonyl group to start the cycle all over again. Beta-oxidation is primarily facilitated by the mitochondrial trifunctional protein, an enzyme complex associated with the inner mitochondrial membrane, although very long chain fatty acids are oxidized in peroxisomes. The overall reaction for one cycle of beta oxidation is: :C''n''-acyl-CoA + FAD + NAD''+'' + H''2''O + CoA → C''n''-2-acyl-CoA + FADH''2'' + NADH + H''+'' + acetyl-CoA Activation and membrane transport Free fatty acids cannot penetrate any biologi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salicylate Poisoning
Salicylate poisoning, also known as aspirin poisoning, is the acute or chronic poisoning with a salicylate such as aspirin. The classic symptoms are ringing in the ears, nausea, abdominal pain, and a fast breathing rate. Early on, these may be subtle, while larger doses may result in fever. Complications can include swelling of the brain or lungs, seizures, low blood sugar, or cardiac arrest. While usually due to aspirin, other possible causes include oil of wintergreen and bismuth subsalicylate. Excess doses can be either on purpose or accidental. Small amounts of oil of wintergreen can be toxic. Diagnosis is generally based on repeated blood tests measuring aspirin levels and blood gases. While a type of graph has been created to try to assist with diagnosis, its general use is not recommended. In overdose maximum blood levels may not occur for more than 12 hours. Efforts to prevent poisoning include child-resistant packaging and a lower number of pills per package. Treatm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adipose Tissue
Adipose tissue (also known as body fat or simply fat) is a loose connective tissue composed mostly of adipocytes. It also contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, Blood vessel, vascular endothelial cells and a variety of White blood cell, immune cells such as adipose tissue macrophages. Its main role is to store energy in the form of lipids, although it also cushions and Thermal insulation, insulates the body. Previously treated as being hormonally inert, in recent years adipose tissue has been recognized as a major endocrine organ, as it produces hormones such as leptin, estrogen, resistin, and cytokines (especially TNF-alpha, TNFα). In obesity, adipose tissue is implicated in the chronic release of pro-inflammatory markers known as adipokines, which are responsible for the development of metabolic syndromea constellation of diseases including type 2 diabetes, cardiovascular disease and atherosclerosis. Adipose tissue is d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fatty Acid
In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated and unsaturated compounds#Organic chemistry, saturated or unsaturated. Most naturally occurring fatty acids have an Branched chain fatty acids, unbranched chain of an even number of carbon atoms, from 4 to 28. Fatty acids are a major component of the lipids (up to 70% by weight) in some species such as microalgae but in some other organisms are not found in their standalone form, but instead exist as three main classes of esters: triglycerides, phospholipids, and cholesteryl esters. In any of these forms, fatty acids are both important diet (nutrition), dietary sources of fuel for animals and important structural components for cell (biology), cells. History The concept of fatty acid (''acide gras'') was introduced in 1813 by Michel Eugène Chevreul, though he initially used some variant terms: ''graisse acide'' and ''acide huileux'' ("acid fat" and "oi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
