Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Metabolism-Biochem
| Question | Answer |
|---|---|
| Fructose Intolerance | Aldolase B LOF-> F1P ins’t metabolized -> reduced available Pi -> reduced gluconeogenesis & glycolysis. Symptoms: Hypoglycemia, jaundice, cirrhosis, vomiting. |
| Essential Fructosuria | Fructokinase LOF-> dietary fructose isn’t trapped in cells -> benign fructosuria & frucosemia |
| Galactosemia | Galactose-1-P Uridyltransferase LOF -> Galactose routed to Galacitol -> toxic accumulation -> Cataracts, MR, Hepatosplenomegaly. |
| Galactokinase Deficiency | Galactosemia & Galactosuria +/- galacitol accumulation. |
| Lactase Deficiency | Age & race dependent. Loss of brush border lactase. Sx: Bloating ,cramps, osmotic diarrhea. |
| Ketogenic Essential AAs | Form Ketone bodies. Lysine, Leucine, Isoleucine, Phenylalanine, Tryptophan, Threonine |
| Glucogenic Essential AAs | Methionine, Valine, Arginine, Histidine, Isoleucine, Phenylalanine, Tryptophan, Threonine |
| Acidic & Basic AAs | Basic: Arginine > Lysine > Histidine (has 0 charge at physiologic pH). Acidic: Aspartate, Glutamate (+ charge at physiologic pH) |
| Hyperammonemia | Hereditary (Ornithine Transcarbamoylase Def) or Acquired (Hepatitis) -> excess NH4+ depletes alpha-Ketoglutarate-> Inhibited TCA cycle. Symptoms: Tremor, slurred speech, somnolence, vomiting, cerebral edema, blurred vision. |
| Phenylalanine Derivatives | Phenylalanine -(phenylalanine hydroxylase)--> Tyrosine* -> Dopa’ -> Dopamine -> NE -> Epi. *Tyrosine -> Thyroxine. ‘Dopa -> Melanin |
| Tryptophan Derivatives | 1) -> Niacin -> NAD/NADP 2) Serotonin -> Melatonin |
| Histidine Derivatives | -> Histamine |
| Glycine Derivatives | Porphyrin -> Heme |
| Arginine Derivatives | 1) -> Creatine 2) -> Urea 3) -> Nitric Oxide |
| Glutamate | 1) -(glutamate decarboxylase + B6)-> GABA 2) -> Glutathione |
| Phenylketonuria | Phenylalanine OHase/Tetrahydrobiopterin LOF-> Phenylalanine not converted to Tyrosine -> Phenylalanine builds up -> MR, growth retardation, fair skin, eczema, musty body odor. Dx: Phenylketones (–acetate, -lactate, -pyruvate) in urine. |
| Alkaptonuria/Ochronosis | Homogentisic Acid Oxidase LOF-> tyrosine not degraded. Signs/Symptoms: Urine turns black on standing, dark connective tissue & arthralgias, otherwise benign. |
| Albinism | Tyrosinase LOF, Tyrosine transporter LOF, or neural crest cell migration failure. |
| Homocystinuria | Homocystine Methyltransferase LOF or Cystathione Synthase LOF/decreased affinity for B6 cofactor. Symptoms: MR, osteoporosis, tall stature, kyphosis, lens subluxation, atherosclerosis (MI/Stroke) |
| Cystinuria | Renal tubule AA transporter LOF -> loss of cystine, ornithine, lysine, arginine in PCT. Symptoms Cystine kidney stones. Treatment: Alkalinize urine w/ Acetazolamide |
| MSUD | Alpha-Ketoacid DeH LOF -> no degradation of Isoleucine, Valine, or Leucine -> CNS problems, MR, Death. |
| Severe Combined Immunodeficiency | Adenosine Deaminase (ADA) Deficiency-> Excess ATP-> feedback inhibition of Ribonucleotide reductase -> prevents DNA synthesis-> reduced T & B Cells (bubble boy) |
| Lesch-Nyhan Syndrome | HGPRT LOF (XR) -> Excessive uric acid production. Signs & Symptoms: MR, SELF-MUTILATION, aggression, hyperuricemia, gout, choreoathetosis. |
| Sources of Gluconeogenesis | Peripheral lactate & alanine, glycerol, propionyl-CoA from odd-chain FA’s. |
| Insulin & Glucagon Action on cAMP | Insulin: lowers cAMP-> lowers PKA. Glucagon: Increases cAMP & PKA |
| Von Gierke’s Disease | G6Phosphatase LOF -> Severe fasting hypoglycemia, elevated blood lactate, uber glycogen in liver & hepatomegaly. |
| Pompe’s Disease | Lysosomal alpha1,4 glucosidase LOF (maltose degradation) -> CARDIOMEGALY, liver & mucle dz. |
| Cori’s Disease | alpha 1,6 glucosidase deficiency -> milder form of Von Gierke’s Disease, w/o elevated blood lactate, and gluconeogenesis is preserved. |
| McArdle’s Disease | Skeletal Muscle Glycogen phosphorylase LOF -> Elevated & undegradable glycogen in muscle-> painful cramps, myoglobinuria. |
| Fabry’s Disease | XR. alpha- Galactosidase A LOF-> ceramide trihexoside accumulation -> stocking & glove neuropathy, CV & Renal disease, angiokeratomas(telangiectasia+wart-like thingy). |
| Gaucher’s Disease | AR. Beta-Glucocerebrosidase LOF -> Cerebroside accumulation -> Hepatosplenomegaly, femur necrosis/bone crises, Gaucher Macrophages (crumpled tissue paper). Presents like leukemias |
| Neimann-Pick Disease | AR. Sphingomyelinase LOF -> sphingomyelin accumulation -> neurodegeneration, hepatosplenomegaly, cherry-red spots on macula (like T-S), foam cells. |
| Tay-Sachs Disease | AR. Hexosaminidase A LOF -> GM2 Ganglioside accumulation -> Neurodegeneration & developmental delay -> Cherry-red spots on macula (like N-P), Onion-skin lysosomes |
| Krabbe’s Disease | AR. Galactocerebrosidase LOF -> Galactocerebroside accumulation -> Optic atrophy & peripheral neuropathy, developmental delay, Goboid cells. |
| Metachromatic Leukodystrophy | AR. Arylsulfatase A LOF -> Cerebroside Sulfate accumulation -> CNS & PNS demyelination w/ ataxia, dementia. |
| Hurler’s Syndrome | AR. Alpha-L-Iduronidase LOF-> Heparan & Dermatan Sulfate accumulation -> Gargoylism, airway obstruction, corneal clouding, hepatosplenomegaly. |
| Hunter’s Syndrome | XR. Iduronate Sulfatase LOF -> Heparan & Dermatan Sulfate accumulation -> less severe Hurler’s sx w/ aggressive behavior, no corneal clouding |
| Cholesterol Ester Transfer Protein | CETP. Transfers cholesterol to other lipoprotein particles |
| Important Lipoproteins | A-I activates LCAT; B-100 Binds LDL receptor, mediates VLDL secretion; C-II co-factor for LPL; B-48 -> chylomicron secretion; E mediates remnant uptake |
| Sucrose, Lactose, Maltose | Sucrose: Fructose + Gluc, Lactose: Galactose +Gluc, Maltose: Gluc+Gluc |
| Cholesterol Synthesis | HMG-CoA -> Mevalonate ->-> Cholesterol. Esterified by lecithin-chol acyltransferase (LCAT) for bile excretion. |
| Essential Fatty Acids | Linoleic & linolenic Acids > Arachidonic acid |
| Type I Dyslipidemia: Hyperchylomicronemia | LPL or C-II LOF -> Elevated Chylomicrons (High serum TGs & chol) |
| Type IIa Dyslipidemia: Hypercholesterolemia | Reduced LDL receptors -> Elevated LDL (High serum Chol (300+ in heteros, 700+ in homos) |
| Type IV Dyslipidemia: hypertriglyceridemia | Hyper production of VLDL-> Elevated serum TGs |
| Methemoglobin | Fe+++ form. High CN- affinity. Produced by nitrite oxidation of Hb + Thiosulfate to renally excrete CN-. METHb can be reversed by METHylene blue. |
| Carboxyemoglobin | CO bound instead of O2 |
| Southern v Northern v Western Blot | S: DNA, N: RNA, W: Protein |
| Ethanol Metabolism | NAD limiting reagent-> . Fomepizole -|Alc DeH (in cytosol). Disulfram -| Acetaldehyde DeH (in mitochondria). High NADH drives pyruvate -> lactate & oxaloacetate-> malate, inhibiting gluconeogenesis -> -> hypoglycemia & FA synthesis -> steatotic liver. |
| Kwashiorkor v. Marasmus | Kwashiorkor: Protein malnutrition -> skin lesions, edema, fatty liver/swollen belly. Marasmus: Energy malnutrition -> tissue wasting +/- edema. |
| De novo Pyrimidine Synthesis | Aspartate Transcarbamylase (ATCase) |
| De novo Purine Synthesis | Glutamine-PRPP Amidotransferase |
| Glycolysis | PFK-1 |
| Gluconeogenesis | Fructose-1,6 Bisphosphatase (FBP-1) |
| TCA Cycle | Isocitrate Dehydrogenase |
| Glycogen Synthesis | Glycogen Synthase |
| Glycogenolysis | Glycogen Phosphorylase |
| HMP Shunt | G6PD |
| FA Synthesis | Acetyl-CoA Carboxylase |
| Fatty Acid Oxidation | Carnitine Acyltransferase I |
| Ketogenesis | HMG-CoA Synthase |
| Cholesterol Synthesis | HMG-CoA Reductase |
| Heme Synthesis | ALA Synthase |
| Urea Cycle | Carbamoyl Phosphate Synthase I |
Created by:
Kyle Tiemeier
Popular USMLE sets