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    Home > Biochemistry News > Biotechnology News > Fat metabolism review notes.

    Fat metabolism review notes.

    • Last Update: 2020-10-23
    • Source: Internet
    • Author: User
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    . 1. What are essential fatty acids?
    some fatty acids can not be synthesized by the body, such as flaxic acid, flaxic acid and peanut tyrenic acid. Need to be ingested from food, so called essential fatty acids.. 2. What is lipoprotein? What is ayl-based carrier protein (ACP)?
    lipids are insoluble or slightly soluble in water, while the fat content in normal human plasma is as high as 500 mg/dl, but the plasma is still clear and transparent. This indicates that lipids in the plasma do not exist in a free state. Instead, it is present and transported in a soluble form, in which free fatty acids (non-esterified fatty acids) in the plasma are transported by
    serum
    protein, and each molecule's clear protein can bind to 10 free fatty acid molecules by means of a non-co-priced bond. The amount of free fatty acids in the plasma is very small, only 5-10% of the total fatty acids in the plasma, and the others are involved in the composition of plasma lipoprotein in the form of esters. Lipoprotein is a multi-component complex of proteins and lipids.
    protein
    lipids are connected by non-co-priced bonds.
    3.The similarity and similarity of oxidation and synthesis of fatty acids were compared.
    fatty acid oxidation process can be summarized as four processes such as β, metastasis, β oxidation, and finally, the production of CO2 and H2O and the release of energy by TATC. AcetylCoA, when fatty acids oxidize in the liver, can produce ketones, but the liver can not use ketones, need to be transported to the liver
    tissue
    oxidation utilization, especially when hungry brain and muscle tissue rely on ketone oxidation to provide energy.
    and the synthesis of fatty acids is in the cell fluid fatty acid synthase system, acetylCoA as raw materials gradually reduced, but the vast majority of acetylCoA first into acetylCoA before participating in the synthesis, and eventually can be synthesized with 16 carbon of soft lipid acid. In the liver mitochondrial and endoensome mesh, acetylCoA and crylCoA are used as raw materials to extend the carbon chain, resulting in longer carbon chain fatty acids. Soft lipid acid as a pregenerant can produce polyunsaturated fatty acids in the body, but essential fatty acids (flaxic acid, flaxic acid and peanut tyrenic acid) in the body synthesis is insufficient and can not be synthesized, must rely on food supply.
    1, the oxidation of fatty acids is first active, in ATP, CoASH, Mg2 plus presence, by the estercoa synthase (endosome, mitochondrial membrane) catalytic production of estercoa.
    transfer of estercoa is carried out in the cell fluid, and the enzyme system that catalytic fatty acid oxidation is in the mitochondrial substrate, so there must be a transfer.
    β : EstercoA enters the mitochondrials and, catalyzed by the fatty acid β oxidase system, performs a four-step continuous reaction of dehydrogenation, watering, hydrogenation and sulfur solution. EsterCoA containing even number of carbon atoms each time through dehydration, watering, rehydration, sulfur to produce a part of acetylCoA, carbon chain shortens 2 carbon atoms, accompanied by 5 ATP generation β;
    It changes to amber coA under the action of carbaboxing, anti-spinase and change to enzyme, the latter being an intermediate product in TAC, which continues to be converted along the TAC into acetic acid, which can be completely oxidized in the body and eventually converted into sugar.
    2, fatty acid synthesis
    fatty acid synthesis site is liver, kidney, lung, breast, adipose tissue in the cell fluid, all contain fatty acid synthase complex, can river bed fatty acids, liver synthesis ability is the strongest. About 8 to 9 times bigger than adipose tissue.
    acetylCoA is first and foremost in mitochondrials, and for fatty acid synthesis it must first enter the cell fluid. There is a citric acid-acetone acid cycle. (AcetylCoA can not freely pass through the mitochondrial membrane, mainly through citric acid-acetone acid circulation into the cytosine: acetylCoA re-mitochondrial body with oxalic acid binding, under the role of citric acid binding enzyme to produce citric acid, citric acid from the mitochondrial membrane carrier into the cytosine, in the cell fluid citric acid lysate decomposing into acetyl A and oxalic acid, acetylCoa participating in the synthesis of acetate.
    acetic acid is produced under the role of
    dride hydrochlorase
    of macarate, which can be transported from the membrane carrier of the mitochondrial to the mitochondrial body. Or appleic acid in the cytostic fluid into acetone acid, and then into mitochondrial, and then acetic acid into oxalic acid, re-participating in the transport of acetylCoA in the mitochondrial body) each time, can make a molecule of acetylCoA into the cytosine, while consuming 2 molecules of ATP, but also to provide the body WITHPH, to supplement the need for a synthetic reaction.
    It is worth noting that the only source of all carbon atoms in the fatty acid molecules synthesized in acetylCoA, but only one molecule of acetylCoA is directly involved in the synthesis process, and the rest can only be synthesized into acetylCoA before entering the path of fatty acid synthesis.
    4. Calculate how much ADP phosphate can be oxidized into CO2 and H2O in the body to produce ATP?
    first look at the oxidation steps of fatty acids: β, transfer, β oxidation and finally entry into TATC are thoroughly oxidized into CO2 and H2O, which
    energy. Lyoic acid is (18:1) and belongs to an even number of carbon atoms.
    1, a molecule of lyicic acid active consumption of 2 molecules of ATP;
    2, transfer time does not consume ATP;
    3, β oxidation: each β oxidation process, dehydrogenation (FADH2, production of 2 ATP), watering, dehydrogenation (NADH plus H, 3 ATP), sulfur solution
    4, acetylCoa into THEC for complete oxidation.
    before, after and after β 8 times to produce 9 acetylCoA, 8 FADH2, 8 NADH. So these produce a total at ATP of 9×12 plus 8× (2 plus 3) , 108 plus 40 plus 148 ATP, minus the 2 ATP consumed at the beginning of the resuming, net generating ATP 146.
    : 16 carbon of filthic acid β oxidation reaction
    16 carbon of soft lipid coA, 7 CoASH, 7FAD, 7NAD, 7 H2O, 8 acetylCoA, 7 FADH2, 7 NADH, 7 H,
    5. What are the special points of oxidation and synthesis of unsaturated fatty acids compared with saturated fatty acids?
    1, unsaturated fatty acids oxidation and saturated fatty acids are basically the same. However, because the β oxidase system requires the action oleic CoA to be a delta2 transstructive configuration, otherwise β oxidation can not continue, and natural unsaturated fatty acids double-bonded multiple-type configuration, so in the process of unsaturated fatty acid oxidation needs to use enzyme-promoting reaction to transform it into delta2 transstructive configuration.
    2, synthesis of unsaturated fatty acids: human and animal tissue contains unsaturated fatty acids mainly soft oleic acid, oleic acid, flaxic acid, peanut tyrenic acid and so on. Important, for example, the most common number of monounsaturated fatty acids - lysic acid and soft phosphate. They can be active by the corresponding saturated fatty acids by desaturated enzymes (presence and sliding endotrification network) catalytic dehydrogenation production, this enzyme only catalytic in delta9 to form a double bond, so flaxic acid, flaxic acid, etc. can not be synthesized in the body or synthesis is insufficient, but they are indispensable to the body, must be supplied by food, so call them essential fatty acids.
    but plants contain desaturation enzymes that form double bonds at delta9??? Re-modify. (The flaxic acid is abundant in fish oil and can be supplemented by food.) )
    6. Can fat be converted into sugar in the body? Why?
    the first step in the aerobic oxidation of sugar is the transformation of acetone acid into acetylCoA, a reaction that is catalyzed by the acetone dehydrogenase complex and is irreversible. So the oxidizing product of fatty acids, acetylCoA, is not converted to acetone acid, in which case the type is not heterogeneic to glucose.
    , glyceroid, a hydrolytic product of fat, can be converted into phosphate and acetone, a substance that can be heterogeneously glucose.
    7. Feeding home ducks with grain, resulting in duck body fat and polylipids, try to describe the metabolic characteristics of this kind of duck during filling?
    reaction of acetylCoA carboxylase is a speed limit step for fatty acid synthesis, and many factors can affect the activity of this enzyme. Thus the speed of fatty acid synthesis changes, the fatty acid synthesis process red other enzymes can also be regulated, such as fatty acid lysase, citric acid lysase.
    After eating in a high-fat diet, or due to hunger led to increased fat mobilization, intracellular soft estercoA increased, can feedback inhibit acetylCoA carbohydrase, thereby limiting the synthesis of fatty acids in the body, but the intake of sugars, sugar metabolism, by sugar oxidation and phosphate sugar cycle provided by acetylCoA and NADPH increase, the increase of these synthetic fatty acids raw materials conducive to the synthesis of fatty acids.
    addition, the increase of sugar oxidation, so that in-cell ATP increased, thereby inhibiting isocric acid dehydrogenase, resulting in the accumulation of isocric acid and citric acid. With the assistance of the corresponding carrier of the membrane in the line granules, from the mitochondrial to the cytosine, acetylCoA carbohydrase can be activated, and itself can be cracked to explain the release of acetylCoA, increasing the raw materials of fatty acid synthesis, so that fatty acid synthesis increases. So feeding ducks with grains (which contain a lot of sugar) can result in fat.
    8. What is ketones? Where is it generated? How do I build it? Where is oxidation? How do I oxidize?
    : Yes??? A normal intermediate metabolite when fatty acids break down oxidation in the liver. It refers specific to acetylacetic acid, β hydroxybutyric acid, and acetone. Among β hydroxybutyric acid content is more, acetone content is very small.
    ketone body production: acetylCoA as raw material, in the liver mitochondrial by enzyme catalysis, first contraction, then lysis to produce ketone body;
    , acetyl CoA is produced by the acetyl CoA of the 2 molecules, while releasing a molecule of CoA. CoACoA633CoA(HMG CoA),CoASH,HMG CoA();
    ,HMG CoAHMGCoA;
    ,β(。 In
    , there is an enzyme system for synthesized ketones, so ketones can be synthesized. However, there is a lack of enzymes in the liver that utilize ketones. Therefore can not oxidize ketone body, need to be transported by blood to the liver tissue further oxidation and decomposition
    ketone body oxidation utilization
    in the mitochondrial cells of the extra-liver tissue, D-β-hydroxybutyric acid through its dehydrogenase action, oxidized to acetylacetic acid, acetylic acid and amberCoA by enzyme catalysis to produce acetylCoA, while releasing amber acid. AcetylCoA is then desulfurized by sulfur to produce 2 molecules of acetylCoA (into the TAC cycle completely oxidized. )
    9. Vertigo patients, the main statement can not eat, fatigue, dizziness, nausea and vomiting, after examination of the blood ketone body significantly increased the urine ketone body positive, diagnosed as ketone uric acidosis. Try to analyze the production of ketosis.
    liver is an organ that produces ketones, but lacks enzymes that use ketones, so ketones are not oxidized in the liver, and the extra-liver tissues lack HMG lysase, which cannot produce ketones, but can use ketones.
    ketone body is a normal intermediate metabolite when the fatty acids in the liver oxidize, is a form of liver energy output, ketone molecules are small, soluble in water, can pass through the blood-brain barrier and muscle capillaries wall, is an important energy source of muscle, especially brain tissue. Brain tissue can hardly oxidize fatty acids, but can use ketones, long-term hunger or lack of sugar supply, ketones will replace glucose as the brain tissue and muscle's main energy source.
    : Under normal circumstances, the amount of ketones in the blood is very small. However, in hunger, high-fat, low-sugar diet and diabetes, fat mobilization is strengthened, fatty acid oxidation increases, and ketones are produced excessively. More than the use of extra-liver tissue on the ketone body, resulting in elevated ketones in the blood, when higher than the ability to recover kidneys, the appearance of ketones in the urine, i.e. ketosis. Acetylacetic acid and D-β hydroxybutyric acid in ketones are relatively strong
    organic
    acids that, if accumulated too much in the body, cause metabolic acidosis.
    : hunger, high-fat diet and diabetes all resulted in reduced utilization rate of sugar oxidation in the body. The ratio of glycosin to insulin was increased, and the concentration of camp increased. cAMP reduces the activity of acetylCoA by increasing the phosphorylation of acetylCoA carbapenemase, thereby reducing the synthesis of acetylCoA, which is also a competitive inhibitor of the speed limit enzyme oxidation of fatty acids, so the activity of the speed limit enzyme is relatively increased, a large number of estercoA transferred to mitochondrials for oxidation, producing a large number of acetylCoA. In addition, mitochondrials, at this time due to the increase of estercoA, especially long-chain esteryl CoA, inhibited citric acid synthase through other structures, resulting in acetylCoA difficult to enter TAC oxidation, the accumulation of acetylCoA in the liver to produce ketones.
    , the ratio of glucosin to insulin increased, resulting in increased lipolyte, then long-chain ester coA increased. Inhibition of citric acid lysase prevents acetylCoA from entering the cell fluid to participate in fatty acid synthesis and accumulate. Too much ketone body will be transported with blood circulation to the liver tissue oxidation utilization, liver tissue oxidizing ketone body by a certain limit, beyond this limit, the blood ketone body on the accumulation, a large number of ketones in the urine, presenting ketosis.
    10. How to describe the synthesis of phospholipids and their main role in lipid metabolism?
    phospholipids are divided into two categories, glycerides phosphate and phospholipids. There are some similarities between the synthesis and explanation process of the two.
    glycelin phospholipid synthesis site all over the body, the whole body of tissue cells containing phospholipid enzymes, can synthesize phospholipids, but to.
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