Flashcards in Biochem metabolism Deck (102):
What are the regulators of phosphofructokinase 1 (PFK1)? (two +, two -)
+ AMP, fructose 2,6 bisphosphate
- ATP, citrate
What are the regulators of fructose 1,6-bisphosphatase? (two +, two -)
+ ATP, acetyl-CoA
- AMP fructose 2,6 bisphosphatase
What are the regulators of isocitrate dehydrogenase? (one +, 2 -)
- ATP, NADH
What is the enzyme needed to take glucose to G6P? Other way?
What is the enzyme needed to take G6P to fructose-6-phosphate?
Where is Hexokinase found in highest quantities? Glucokinase?
Hexokinase = most tissues
Glucokinase = Liver and Beta cells of pancreas
What is the equation for Km, if K1 = rate from substrates to enzyme/substrate complex, K2 = rate from complex back to substrates, and K3 = rate from complex to products?
Km = (K2+K3)/K1
Which is induced by insulin, hexokinase, or glucokinase?
Which is feedback inhibited by glucose, hexokinase or glucokinase?
Which has a gene mutation that is associated with maturity onset DM, hexokinase or glucokinase?
What is the MOA or Arsenic?
Blocks ATP generation by phosphoglycerate kinase
What are the two downregulators of hexokinase?
What are the only two amino acids that are strictly ketogenic?
Lysine and Leucine
What are the findings of pyruvate dehydrogenase deficiency?
Neurological defects, lactic acidosis
What is the treatment for pyruvate dehydrogenase deficiency?
Increase ketogenic nutrients
What is the cofactor that is needed to keep glutathione reduced? What happens if this enzyme is impaired?
What is the enzyme that uses NADH to reduce glutathione? Oxidize it?
What is the cause of essential fructosuria? Symptoms?
Fructokinase does not function properly. Benign loss of fructose in urine.
What is the enzymatic cause of fructose intolerance?
Deficiency of aldolase B
What is the effect of galactokinase deficiency?
Galactouria, infantile cataracts,
What is the cause of classic galactosemia? Symptoms = ?
Absence of galactose-1-phosphate uridyltransferase
Symptoms = Infantile cataracts, MR, jaundice
What is the enzyme that converts glucose to sorbitol? Sorbitol to fructose?
Why is it that DM can damage the eye?
Eye only has aldose reductase, therefore there is an accumulation of sorbitol
Which type of aminoacids are needed, L or D?
What are the three amino acids that are only glucogenic?
What are the two acidic amino acids?
What are the three basic amino acids?
What are the substrates of the urea cycle? (hint: Ordinarily, careless crappers are frivolous about urination)?
Why is it that hyperammonemia leads to inhibition of the TCA cycle?
Loss of alpha-keto glutarate
What is the treatment for hyperammonemia? What are the two drugs that can be given?
Limit protein intake
What is the MOA of lactulose?
Acidify's the Gi tract to trap NH4
What is the cause of n-acetylglutamate deficiency (what enzyme is affected)?
A required cofactor for carbamoyl phosphate synthetase I
What is the universal NH4 carrier?
Glutamate/ alpha ketoglutarate
What is ornithine transcarbamylase deficiency? Mode of inheritance? How is it diagnosed?
XLR loss of ornithine transcarbamylase
Orotic acid increased in the blood
What is the most common urea cycle disorder (which enzyme is deficient)?
ornithine transcarbamylase deficiency
What is the rxn that ornithine transcarbamylase catalyses"
Ornithine to citrulline
Orotic acid increased in the blood = ?
Ornithine transcarbamylase deficiency
What is the vitamin necessary to convert Y to niacin?
What is the vitamin necessary to convert histidine to histamine?
What is the enzyme necessary to convert E to GABA?
What are the two possible causes of phenylketonuria? (enzyme/cofactor)
Deficiency or defect in phenylalanine hydroxylase or THF cofactor
What are the symptoms of phenylketonuria?
Musty body odor
Musty baby = ?
What is the treatment for phenylketonuria?
Decrease F, increase Y.
What is the cause of alkaptonuria?
Deficiency of homogentisate oxidase (in degradation of Y to fumarate)
What are the symptoms of alkaptonuria?
Dark CT, brown pigmented sclera
Urine turns black
What are the three causes of homocystinuria?
1. Cystathionine beta-synthase deficiency (CBS)
2. Decreased affinity of cystathionine synthase for PPP
3. Homocysteine methyltransferase deficiency
What are the symptoms of homocystinuria?
Increased homocysteine in urine
Review methionine to Cysteine pathway.
What are the causes of cystinuria?
Defect in AA transporter for COLA (cysteine, Ornithine, Lys, Arg)
What is the cause of maple syrup urine disease? What is the enzyme that is involved?
Blocked degradation of branched AAs (I, L, V)
Alpha ketoacid dehydrogenase
What are the three AAs that are blocked in maple syrup urine disease?
(I love vermont)
What are the symptoms of maple syrup urine disease?
Maple syrup urine
What is the treatment for maple syrup urine disease?
Restrict Leucine, Isoleucine, and valine
What is the bond between glycogen monomers (glucose)?/ What about the branches of the polymer?
alpha (1,6) for branches
What are the two metabolites that come from the degradation of glycogen?
What are the two enzymes that are needed for glycogenolysis?
What is the receptor for insulin?
Y kinase dimer
What is the receptor for glucagon?
G protein with PKA and calmodulin
What are the enzymes responsible for the synthesis of glycogen?
What are the monomers that are added to a growing glycogen chain?
What are the two intermediates of glucose to glycogen?
What is type I GSD? What is the enzyme that is deficient?
What is type II GSD? What is the enzyme that is deficient? Symptoms?
Pompe's trashes the pump (heart, liver, muscle failure)
What is type III GSD? What is the enzyme that is deficient?
What is type V GSD? What is the enzyme that is deficient? Symptoms?
Muscle glycogen phosphorylase
What is the enzyme that is deficient in Hunter's syndrome? Mode of inheritance?
What is the enzyme that is deficient in Hurler's syndrome? Mode of inheritance?
What is the enzyme that is deficient in fabry's disease? Symptoms? What accumulates?
What is the enzyme that is deficient in Gaucher's disease? Symptoms? What accumulates?
Crumpled tissue paper macrophages
What is the enzyme that is deficient in Niemann-Pick's disease? Symptoms? What accumulates?
(No Man picks his nose with his sphinger
What is the enzyme that is deficient in Tay-Sach's disease? Symptoms? What accumulates?
(tay sax lacks hexosaminidase)
What is the enzyme that is deficient in Krabbe disease? Symptoms? What accumulates?
Peripheral neuropathy, MR
What is the enzyme that is deficient in Metachromatic leukodystrophy? Symptoms? What accumulates?
Central and peripheral demyelination
What is carnitine deficiency?
Inability to transport LCFAs into mito, causing weakness, hypotonia
What is acyl-coa dehydrogenase deficiency?
Inability to transport carnitine inside the mito, d/t lack of carrier.
What is the enzyme that transports FAs into the mitochondria? What is the intermediate produce between the two?
Carnitine palmitoyl transferase I and II
What are FAs metabolized to, and is measured in DKA?
What is the rate limiting step of Cholesterol synthesis? (name the enzyme involved)
What is the MOA of statins?
Inhibit HMG-CoA reductase
What is the enzyme that breaks down dietary triglycerides in the small intestines?
What is the enzyme that degrades Tgs circulating in chylomicrons and VLDLs?
Lipoprotein lipase (LPL)
What is the function of apoprotein A?
activators of LCAT
What is the function of apoprotein B?
What is the function of lipoprotein C?
Modulate the function of LPL
What is the function of lipoprotein E?
What is the lipase that degrades TGs stored in adipocytes?
Hormone sensitive lipase
What is the function of LCAT?
Catalyzes esterification of cholesterol
Can the body breakdown cholesterol?
What is the enzyme that transports cholesterol out of a cell into HDL, in order to form LDL? What is the enzyme that takes the cholesterol, and transfers to HDL particles?
What is the function of LDL?
Transports cholesterol from the Liver to body
What is the function of HDL?
Transports cholesterol from the body to liver
What is the effect of EtOH on HDL synthesis?
What is Type I hypercholesterolemia?
AR lipoprotein lipase deficiency
What is type II hypercholesterolemia?
AD absent LDL receptors
What is type IV hypercholesterolemia?
AD hepatic overproduction of VLDLs
Which type of hypercholesterolemia: increased chylomicrons, TG, and cholesterol
Which type of hypercholesterolemia: Increased LDLs, cholesterol
Which type of hypercholesterolemia: increase VLDL, Tgs
Which type of hypercholesterolemia: hyperchylomicronemia
Which type of hypercholesterolemia: familial hypercholesterolemia