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20 Cards in this Set
- Front
- Back
How are Amino Acids utilized in different nutritional states?
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Fed State:
AA carbon --> glucose --> glycogen (energy storage) AA carbon (excess AAs) --> acetyl CoA (fatty acid) --> triglycerides (adipose tissue) energy storage Fasting State: AA carbon -CO2 -pyruvate -TCA cycle intermediates -acetyl CoA, acetoacetate (all for energy production) |
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Why are amino acids glucogenic, ketogenic or both?
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Glucogenic - AA can be converted into glucose
Ketogenic - AA can be converted into ketone bodies Glucogenic & Ketogenic - AA can be converted into both glucose and ketone bodies |
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What are the glucogenic AA's?
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-Alanine
-Arginine -Asparagine -Aspartate -Cycteine -Glutamate -Glutamine -Glycine -Proline -Serine -histidine -methionine -valine |
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What are the ketogenic AA's?
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-leucine
-lysine (The ones that start with "L") |
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What are the AA's that are both glucogenic and ketogenic?
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-tyrosine
-threonine -isolucine -phenylalanine -tryptophan (ones that start with "T" plus 2--isolucine & phenylalanine) |
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What are the essential AA's?
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-pretty much all the glucogenic ones except for histidine, methionine, and valine
-tyrosine |
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What are the main pathways for the synthesis of nonessential AA's?
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-AA's synthesized from glycolysis intermediates
-tyrosine -AA's synthesized from alpha-ketoglutarate -AA's synthesized from oxaloacetate |
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What are the characteristic enzyme deficiencies in diseases of AA metabolism?
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-Pyridoxal-phosphate ---> transamination & deamination
-tetrahydrofolate ---> metabolism of serine glycine, methionine and histidine -B12 Vitamin ---> methionine metabolism -Thiamine-pyrophosphate (B1) and lipoate ---> oxidative decarboxylation of branched chain AA's (those 4 are derived from vitamins) tetrahydrobiopterin ---> hydroxylation of phenylalanine, tyrosine, and tryptophan |
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What are the metabolites that have abnormal levels in diseases of AA metabolism?
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look at disease chart on last slide of lecture
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What is Homocystinuria?
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cystathione synthase, or vitamin B6, B12, or folic acid deficiency
AA metabolism: Methionine Accum. metaboilites: homocysteine, methionine Symptoms: myocardial infarction, mental retardation, ectopia lentis |
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What is the maple syrup urine disease?
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a-keto acid dehydrogenase deficiency
AA metabolism: Leu, Ile, Val (I Love Vermont maple syrup) Accum. metabolites: Leu, Ile, Val and their a-ketoacids Symptoms: maple syrup odor of urine, neurological problems treatment: diet restricted in branched chain AA (BCAA) |
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What is Phenylketonuria?
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phenylalanine hydroxylase or tetrahydrobiopterine deficiency
AA metabolism: Phe Accum. metabolites: Phe, phenyllactate, phenylacetate, phenylpyruvate Symptoms: musty odor of urine, neurological problems, hypopigmentation treatment: Phe-restricted, Tyr supplemented diet, avoid aspartame |
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What is Albinism?
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tyrosinase is deficient
AA metabolism: Tyr Accum. metabolites: none Symptoms: white skin, hair, pink eyes |
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What is Tyrosinemia 1?
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fumaryl acetoacetate hydrolase deficiency
AA metabolism: Tyr Accum. metabolites: succinylacetone, fumarylacetoacetate Symptoms: liver failure, kidney failure treatment: dietary restriction of phenylalanine and tyrosine |
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What is Alkaptonuria?
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homogentisate oxidase deficiency
AA metabolism: Tyr Accum. metabolites: homogentisic acid accumulates in urine Symptoms: urine turns dark, black pigmentation in eye, ear arthritis |
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What are the major end products of amino acid degradation?
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-pyruvate
-TCA cycle intermediates (oxaloacetate, fumarate, succinyl CoA, a-ketoglutarate) -acetyl-coa, acetoacetate |
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Asparaginase is used as what?
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antileukemic drug
-asparagine is required for growth of fast dividing leukemic cells (AA's that are degraded to oxaloacetate) |
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histidinemia
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-disease due to a deficiency in histidase
-elevated levels of histidine in blood and urine |
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folic acid deficiency
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-excrete increased amounts of FlGlu in urine
-FlGlu excretion used to monitor folic acid deficiency |
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Pellagra
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lack of tryptophan and niacin (vit B3) in diet
-4 D's: Dermatitis, Diarrhea, Dementia, and if untreated Death! |