FA biochem 5

Card Set Information

Author:
Neda317
ID:
293633
Filename:
FA biochem 5
Updated:
2015-01-23 15:13:54
Tags:
biochem
Folders:

Description:
biochem
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user Neda317 on FreezingBlue Flashcards. What would you like to do?


  1. Essential Amino acids
    Glucogenic
    Glucogenic/ketogenic
    Ketogenic
    • Glucogenic: methionine (Met), valine (Val),histidine (His).
    • Glucogenic/ketogenic: isoleucine (Ile),phenylalanine (Phe), threonine (Thr),tryptophan (Trp).
    • Ketogenic: leucine (Leu), lysine (Lys).
  2. Acidic Amino acids and what's the charge in body PH?
    • Aspartic acid (Asp) and glutamic acid (Glu).
    • Negatively charged at body pH.
  3. Basic Amino acids
    • Arginine (Arg), lysine (Lys), histidine (His).
    • Arg is most basic. His has no charge at body pH.
  4. what Amino acids are required during periods of growth.
    Arg and His
  5. What histones r made of?
    Arg and Lys are high in histones, which bind negatively charged DNA.
  6. Hyperammonemia
    Can be acquired (e.g., liver disease) or hereditary(e.g., urea cycle enzyme deficiencies).Results in excess NH4+, which depletes α-ketoglutarate, leading to inhibition of TCA cycle.
  7. Hyperammonemia Treatment:
    limit protein in diet. Benzoate or phenylbutyrate (both of which bind amino acid and lead to excretion) may be given to dec ammonia levels. Lactulose to acidify the GI tract and trap NH4+ for excretion.
  8. Ammonia intoxication
    tremor (asterixis),slurring of speech, somnolence, vomiting,cerebral edema, blurring of vision.
  9. N-acetylglutamate deficiency
    Required cofactor for carbamoyl phosphate synthetase I. Absence of N-acetylglutamateŽ --> hyperammonemia.
  10. N-acetylglutamate deficiency Presentation is identical to _____ However the difference is ____
    • carbamoyl phosphate synthetase I deficiency
    • However, inc ornithine withnormal urea cycle enzymes suggests hereditary N-acetylglutamate deficiency.
  11. Ornithine transcarbamylase deficiency
    Most common urea cycle disorder. X-linked recessive (vs. other urea cycle enzyme deficiencies,which are autosomal recessive). Interferes with the body’s ability to eliminate ammonia. Often evident in the first few days of life, but may present with late onset. Excess carbamoyl phosphate isconverted to orotic acid (part of the pyrimidine synthesis pathway).
  12. Ornithine transcarbamylase deficiency Findings
    Findings: inc orotic acid in blood and urine,  BUN, symptoms of hyperammonemia. No megaloblastic anemia (vs. orotic aciduria).
  13. Phenylketonuria due to
    dec phenylalanine hydroxylase or dec(THB) tetrahydrobiopterin (aka dihydrobiopterin reductase) cofactor (malignantPKU).
  14. in Phenylketonuria (PKU) what aa becomes essential? 
    Tyrosine becomes essential
  15. PKU findings and tx:
    • intellectual disability, growth retardation, seizures, fair skin, eczema, musty body odor. 
    • Treatment: dec phenylalanine and  tyrosine in diet.
    • PKU patients must avoid the artificial sweetener aspartame, which contains phenylalanine.
  16. Maternal PKU—
    lack of proper dietary therapy during pregnancy. Findings in infant:microcephaly, intellectual disability, growth retardation, congenital heart defects.
  17. PKU disorder of what aa?
    Disorder of aromatic amino acid metabolism    --> musty body odor.
  18. Alkaptonuria(ochronosis)Congenital deficiency of
    homogentisate oxidase
  19. Alkaptonuria(ochronosis) Findings:
    Findings: dark connective tissue, brown pigmented sclerae, urine turns black on prolonged exposure to air. May have debilitating arthralgias (homogentisic acid toxic to cartilage).
  20. Homocystinuria deficiency in ___ and tx ___ 
    3 of them 
    • 1)Cystathionine synthase deficiency
    • (treatment: dec methionine, inc cysteine,  inc B12 and folate in diet)ƒƒ
    • 2) dec affinity of cystathionine synthase for pyridoxal phosphate (treatment: inc B6 and inc cysteine in diet)
    • 3) ƒƒHomocysteine methyl transferase (methionine synthase) deficiency (treatment: methionine in diet)
  21. Homocystinuria findings 
    All forms result in excess homocysteine. Findings: high homocysteine in urine, intellectual disability, osteoporosis,joint contractures, tall stature Marfan-like, kyphosis,lens subluxation (downward and inward),thrombosis, and atherosclerosis (stroke andMI).
  22. Cystinuria Hereditary defect of
    Hereditary defect of renal PCT and intestinal amino acid transporter for Cysteine, Ornithine,Lysine, and Arginine (COLA).Excess cystine in the urine can lead to precipitation of hexagonal cystine stones.
  23. Cystinuria diagnosis? and tx? 
    • Urinary cyanide-nitroprusside test is diagnostic.
    • Treatment: urinary alkalinization (e.g.,potassium citrate, acetazolamide) and chelating agents  solubility of cystine stones;good hydration.
  24. Cystine is made of
    Cystine is made of 2 cysteines connected by a disulfide bond.
  25. Maple syrup urine disease due to
    Blocked degradation of branched aminoacids (Isoleucine, Leucine, Valine) due to α-ketoacid dehydrogenase (B1). Causes α-ketoacids in the blood, especially those of leucine
  26. name Glycogen storage diseases
    • Very Poor Carbohydrate Metabolism
    • Von Gierke disease(type I)
    • Pompe disease(type II)
    • Cori disease(type III)
    • McArdle disease(type V)
  27. Von Gierke disease(type I)
    findings
    enzyme def
    • findings: Severe fasting hypoglycemia, high glycogen in liver, high blood lactate, hepatomegaly
    • DEFICIENT ENZYME: Glucose-6-phosphatase 
    • G6P ---> Glucose 
  28. Pompe disease(type II)
    findings
    enzyme def
    • Pompe trashes the Pump(heart, liver, and muscle). Autosomal recessive
    • findings: Cardiomyopathy and systemic findings leading to early death

    DEFICIENT ENZYME: Lysosomal α-1,4-glucosidase (acid maltase)
  29. Cori disease(type III)
    findings
    enzyme def
    • findings: Milder form of type I with normal blood lactate levels
    • Autosomal recessive.Gluconeogenesis is intact
    • DEFICIENT ENZYME: Debranching enzyme (α-1,6-glucosidase)
  30. McArdle disease(type V)
    findings
    enzyme def
    • Autosomal recessive. McArdle = Muscle.
    • findings: inc glycogen in muscle, but cannot break it down, leadingto painful muscle cramps, myoglobinuria (red urine)with strenuous exercise, and arrhythmia from electrolyte abnormalities.
    • DEFICIENT ENZYME: Skeletal muscle glycogen phosphorylase(myophosphorylase)
  31. Lysosomal storage  diseases Sphingolipidoses are
    • Fabry disease
    • Gaucher disease
    • Niemann-Pick disease
    • Tay-Sachs disease
    • Krabbe disease
    • Metachromatic leukodystrophy
  32. Lysosomal storage  diseases 
    Mucopolysaccharidoses are
    • Hurler syndrome
    • Hunter syndrome
  33. Fabry disease 
    FINDINGS
    DEFICIENT ENZYME
    ACCUMULATED SUBSTRATE
    • FINDINGS: Peripheral neuropathy of hands/feet, angiokeratomas, cardiovascular/renal disease
    • ENZYME: α-galactosidase A
    • ACCUMULATED: Ceramide & trihexoside
    • INHERITANCE: XR
  34. Gaucher disease
    FINDINGS & TX
    DEFICIENT ENZYME
    ACCUMULATED SUBSTRATE 
    INHERITANCE
    • FINDINGS & TX:Most common.Hepatosplenomegaly, pancytopenia,aseptic necrosis of femur, bone crises, Gaucher cells (lipidladen macrophages resembling crumpled tissue paper); treatment is recombinant glucocerebrosidase.
    • ENZYME : Glucocerebrosidase (β-glucosidase)
    • ACCUMULATED: Glucocerebroside 
    • INHERITANCE: AR
  35. Niemann-Pick disease
    FINDINGS
    DEFICIENT ENZYME
    ACCUMULATED SUBSTRATE 
    INHERITANCE
    • finding: Progressive neurodegeneration, hepatosplenomegaly,cherry-red”spot on macula, foam cells (lipidladen macrophages)
    • enzyme: Sphingomyelinase
    • Accumulated: Sphingomyelin

    • INHERITANCE: AR
  36. Tay-Sachs disease
    FINDINGS
    DEFICIENT ENZYME
    ACCUMULATED SUBSTRATE 
    INHERITANCE
    • findings: Progressive neurodegeneration, developmental delay, “cherry-red”spot on macula, lysosomes with onion skin, no hepatosplenomegaly(vs. Niemann-Pick) 
    • enzyme: Hexosaminidase A 
    • accumulated: GM2 ganglioside 
    • INHERITANCE: AR
  37. Krabbe disease
    FINDINGS
    DEFICIENT ENZYME
    ACCUMULATED SUBSTRATE 
    INHERITANCE
    • findings: Peripheral neuropathy, developmental delay, optic atrophy, globoid cells
    • enzyme: Galactocerebrosidase

    • accumulated: Galactocerebroside, psychosine
    • INHERITANCE: AR
  38. Metachromatic leukodystrophy
    FINDINGS
    DEFICIENT ENZYME
    ACCUMULATED SUBSTRATE 
    INHERITANCE
    • finding: Central and peripheral demyelination with ataxia, dementia 
    • enzyme: Arylsulfatase A
    • accumulated: Cerebroside sulfate
    • inher: AR

  39. Acyl-CoA dehydrogenase deficiency
    high dicarboxylic acids,low  glucose and ketones. Acetyl-CoA is a (+) allosteric regulator of pyruvate carboxylase in gluconeogenesis. low acetyl-CoA Ž--> low fasting glucose.
  40. Carnitine deficiency
    • Long-chain fatty acid degradation requires carnitine-dependent transport into the mitochondrial matrix
    • Carnitine deficiency: inability to transport LCFAs into the mitochondria, resulting in toxic accumulation. Causes weakness,hypotonia, and hypoketotic hypoglycemia. 

    • “SYtrate” = SYnthesis.
    • CARnitine = CARnage of fatty acids.
  41. Hurler syndrome
    FINDINGS
    DEFICIENT ENZYME
    accumulated:
    inher:
    • finding: Developmental delay, gargoylism,airway obstruction, corneal clouding,hepatosplenomegaly 
    • enzyme: α-L-iduronidase 
    • accumulated: Heparan sulfate,dermatan sulfate
    • inher: AR
  42. Hunter syndrome
    FINDINGS
    DEFICIENT ENZYME
    accumulated:
    inher:
    • finding: Mild Hurler + aggressive behavior, no corneal clouding 
    • Enzyme: Iduronate sulfatase
    • accumulated: Heparan sulfate,dermatan sulfate
    • inher: XR
  43. Ketone bodies
    In the liver, fatty acids and amino acids are metabolized to acetoacetate and β-hydroxybutyrate (to be used in muscle and brain). In prolonged starvation and diabetic ketoacidosis, oxaloacetate is depleted for gluconeogenesis. In alcoholism, excess NADH shunts oxaloacetate to malate. Both processes cause a buildup of acetyl-CoA, which shunts glucose and FFA toward the production of ketone bodies.
  44. Rate-limiting step in Cholesterol synthesis
    HMG-CoA reductase (induced by insulin), which converts HMG-CoA to mevalonate. 
  45. Lipid transport, key enzymes 
    6 of them
    • 1- Pancreatic lipase—degradation of dietary triglycerides (TG) in small intestine.
    • 2-Lipoprotein lipase (LPL)—degradation of TG circulating in chylomicrons and VLDLs. Found on vascular endothelial surface.
    • 3- Hepatic TG lipase (HL)—degradation of TG remaining in IDL.
    • 4- Hormone-sensitive lipase—degradation of TG stored in adipocytes.
    • 5- LCAT—catalyzes esterification of cholesterol.
    • 6- Cholesterol ester transfer protein (CETP)— mediates transfer of cholesterol esters to other lipoprotein particles(VLDL, IDL, LDL) 
  46. Apo-E func 
    • Mediates remnant uptake
    • present on all except LDL 
  47. Apo-A-I function 
    • Activates LCAT
    • present on chylomicron and HDL 
  48. Apo - C-II func
    • Lipoprotein lipase cofactor 
    • present on chylomicron and VLDL and HDL 
  49. Apo- B-48
    • Mediates chylomicron secretion
    • present on Chylomicron and Chylomicron remnant
  50. Apo-B-100 
    • Binds LDL receptor
    • present on VLDL, IDL, LDL
  51. Lipoprotein functions
    Lipoproteins are composed of varying proportions of cholesterol, TGs, and phospholipids. LDL and HDL carry most cholesterol. LDL transports cholesterol from liver to tissues. HDL transports cholesterol from periphery to liver.
  52. Chylomicron
    Delivers dietary TGs to peripheral tissue. Delivers cholesterol to liver in the form of chylomicron remnants, which are mostly depleted of their triacylglycerols. Secreted by intestinal epithelial cells.
  53. VLDL
    Delivers hepatic TGs to peripheral tissue. Secreted by liver.
  54. IDL
    Formed in the degradation of VLDL. Delivers TGs and cholesterol to liver.
  55. LDL
    Delivers hepatic cholesterol to peripheral tissues. Formed by hepatic lipase modification of IDL in the peripheral tissue. Taken up by target cells via receptor-mediated endocytosis.
  56. HDL
    Mediates reverse cholesterol transport from periphery to liver. Acts as a repository for apoC and apoE (which are needed for chylomicron and VLDL metabolism). Secreted from both liver and intestine. Alcohol inc. synthesis.
  57. Familial dyslipidemias types 
    • 1) I—hyperchylomicronemia
    • 2) IIa—familial hypercholesterolemia
    • 3) IV—hypertriglyceridemia
  58. I—hyperchylomicronemia 
    INCREASED BLOOD LEVEL
    PATHOPHYSIOLOGY
    • -Chylomicrons, TG, cholesterol
    • -AR. Lipoprotein lipase deficiency or altered apolipoprotein C-II. Causes pancreatitis, hepatosplenomegaly, and eruptive/pruritic xanthomas (no high risk for atherosclerosis).
  59. IIa—familial hypercholesterolemia
    INCREASED BLOOD LEVEL
    PATHOPHYSIOLOGY
    • -LDL, cholesterol
    • AD. Absent or defective LDL receptors. Heterozygotes (1:500) havecholesterol ≈ 300 mg/dL; homozygotes (veryrare) have cholesterol ≈ 700+ mg/dL. Causes accelerated atherosclerosis (may have MI before age 20), tendon (Achilles) xanthomas, and corneal arcus.
  60. IV—hypertriglyceridemia 
    INCREASED BLOOD LEVEL
    PATHOPHYSIOLOGY
    • - VLDL, TG
    • AD. Hepatic overproduction of VLDL. Causes pancreatitis.

What would you like to do?

Home > Flashcards > Print Preview