large quantity of ketone bodies in the blood Ketoacidosis Dangerous lowering of

Large quantity of ketone bodies in the blood

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large quantity of ketone bodies in the blood Ketoacidosis: Dangerous lowering of blood pH brought on by ketosis Amino Acid Catabolism Proteins used for catabolism are derived either from diet or those already found in the cytosol. Dietary proteins are broken down into amino acids subunits and absorbed by the digestive tract o Immediately delivered to the liver o Amino acids = carbon skeleton bound to an amino group o Nitrogen in amino group is not used for energy Removed via transamination Remaining carbon skeleton can be oxidized for fuel Events of protein catabolism occur in the following sequence: 15 Fatty Acid Catabolism
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o Transamination: amino group is removed and transferred to alpha- ketoglutarate Results in a carbon skeleton and the amino acid glutamate Carbon skeleton can be converted into a variety of compounds, which can then be oxidized o Oxidative deamination: in the mitochondria of hepatocytes, glutamate undergoes oxidative deamination Produces ammonia and alpha-ketoglutarate Some of amino groups removed are used in the synthesis of new amino acids Remaining ammonia molecules are removed by the urea cycle o Urea: formed when two ammonia molecules are combined with carbon dioxide Eliminated by the kidneys in the urine Amino Acid Catabolism Nutrient Catabolism
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Anabolic Pathways Anabolism o Synthesis of large molecules Requires energy Serves many vital purposes: Nutrient storage and synthesis Structural element synthesis Synthesis of special molecules such as FAD and NAD+ Store nutrients for two reasons: o When intake from diet exceeds amount of energy immediately required o When body needs a ready supply of nutrients to oxidize for maintaining metabolic homeostasis between meals o Glycogen and adipose are the two main storage forms Glucose Anabolism 17 Nutrient Anabolism
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Glyconeogenesis: Storage of excess glucose obtained from diet o Synthesis of glycogen via a series of enzyme catalyzed reactions o Occurs mostly in hepatocytes and skeletal muscle fibers o Add glucose units to growing storage molecule o Glycogen- large branched molecule composed of thousands of glucose units Glycogenolysis: catabolic process that cleaves glucose units off of glycogen to maintain blood glucose homeostasis Gluconeogenesis: Mechanism by which glucose is synthesis from noncarbohydrate molecules o Kicks in once glycogen supplies have been exhausted o Hepatocytes and specific kidney cells convert three- and four-carbon compounds into glucose o Potential substrates include: Glycerol from triglyceride catabolism Pyruvate and lactate Intermediate compounds from the citric acid cycle Specific glucogenic amino acids Fatty acid cannot be converted into new glucose molecules Fatty Acid Anabolism Synthesis of fatty acids resemble beta-oxidation in reverse 18
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o Involves a completely different pathway, enzymes, and manufacturing location Lipogensis:
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