Biochemistry Flashcards
Glycolysis
Phosphofruktokinase-1 (PFK-1)
Gluconeogenesis
Fructose-1,6-bisphosphate
TCA cycle
Isocitrate Dehydrogenase
Glycogen synthesis
Glycogen synthase
Glycogenolysis
Glycogen phosphorylase
HMP shunt
Glucose 6 phosphate dehydrogenase (G6PD)
De novo pyrimidine synthesis
Carbamoyl phosphate synthetase II
De novo purine synthesis
Glutamine PRPP amidotransferase
Urea Cycle
Carbamoyl phosphate synthetase I
Fatty Acid Oxidation
Carnitine acyltransferase I
Fatty acid synthesis
Acetyl CoA carboxylase
Ketogenesis
HMG-CoA synthase
Cholesterol Synthesis
HMG-CoA reductase
glucose to glucose-6-phosphate
Hexokinase High affinity (low Km), uninduced by insulin
glucose to glucose-6-phosphate in liver and B-cells of pancrease
Glucokinase
low affinity (high Km), induced by insulin
phophorylates excess glucose
Carries amino acids to liver from muscle
alanine
Location of TCA
mitochondria
NADPH
Reduces Glutathione def = hemolytic anemia, heinz bodies, bite cells
Fructose intolerance:
hypoglycemia, jaundice, cirrhosis, vomiting
def of Aldolase B
Amino Acids required during growth
Arg and His.
Are increased in histones, which bind neg charged DNA
Hyperammonemia: acquired or urea cycle enzyme def
Results in excess NH4, which depletes alpha-ketoglutarate, leading to inhibition of TCA
MC urea disorder. Excess carbamoyl phosphate is converted to orotic acid.
Ornithine transcarbamoylase deficiency.
results in hyperammonemia
Phenylalanine derivatives
–>Tyrosine –> Dopa –> dopamine –> NE –>Epi
melanin comes from Dopa
Tryptophan derivatives
B6 –> Niacin –> NAD/NADP
or
BH4 –> serotonin –> melatonin
Glutamate derivatives
B6 –> GABA
Mental retardation, growth retardation, sezures, fair skin, musty odor, infant
Phenylketonuria def phenylalanine hydroxylase
dark connective tissue and urine turns black on prolonged exposure to light
Alkaptonuria def of homogentisic acid oxidase
Albanism
deficiency of tyrosine, defective tyrosine transporters, or lack of migration of neural crest cells.
Inc homosystein in urine, mental retardation, tall, lens sublexation, athrosclerosis
Homocystinuria
- cystathione synthase deficiency
- def B6
- Homocysteine methyltransferase (req B12)
Cystinuria
Staghorn calculi
Maple syrup urine
def of alpha-ketoacid dehydrogenase. blocks degradation of branched amino acids
tryptophan excreted in urine and decreased absorption in gut
Hartnups. Leads to pellagra
Von Gierkes disease
Glucose-6-phosphate def
Pompe’s disease
Lysosomal alpha 1,4 glucosidase
Cori’s Disease
Debranching enzyme (alpah-1,6-glucosidase
McArdles:
painful muscle cramps, myoglobinuria with strenuous exercise.
glycogen phosphorylase def in skeletal muscle
peripheral neuropathy of hands and feet, angiokeratomas, cardio/renal disease
Fabry’s: a-galctosidase A def
Hepatosplenomegaly, crumpled up tissue cells
Gaucer’s disease: Glucocerbrosidase def
cherry red spots on macula, neurodegeneraion, hepatosleenomegally
Niemann-picks disease: sphingomyelinase def
cherry red spots on macula, neurodegeneraion, No hepapatospleenomegaly
Tay-sachs: Hexosaminidase A
Peripheral neruopathy with optic atrophy, developmental delay
Krabbe’s disease: B-galactocerebrosidase
Central and perish demylination with ataxia and dementia
Metachromatic leukodystrophy: arylsulfatase A def
Developmental delay, gargoylism, airway obstruction, corneal clouding
Hurler’s: a-L-iduronidase
Accumulation of: Heparn and dermatan sulfate
agressive behavior, no corneal clouding, mild hurlers
Hunter’s: Iduronate sulfatase def.
accumulation: Heparan and Dermatan sulfate.
XR
Cholesterol Synthesis
HMG-CoA reductase
“-statins” inhibit
Mediates remnant uptake
Apo-E
Mediates cylomicron secretion
Apo-B48
Binds LDL receptor
Apo-B100
Transports cholesterol from liver to tissue
LDL
Transports cholesterol from periphery to liver
HDL
Delivers dietary TG to peripheral tissue. Delivers cholesterol to liver.
Chylomicron
Delivers hepatic TG to peripheral tissue. Secreted by liver.
VLDL
Formed tin the degredation of VLDL. Delivers TG and cholesterol to liver.
IDL
Delivers hepatic cholesterol to peripheral tissue. formed by lipoprotein lipase
LDL
Acts as a repository for Apo E and Apo C (which are needed for chylomicron and VLDL metabolism)
HDL
Increased chylomicrons in blood, pancreatitis, hepatomegaly, pruitic xanthomas
hyper-chylomicronemia.
Lipioprotein lipase deficiency or altered Apo C2.
accelerated atherosclerosis, tendon xanthomas, and corneal arcus
Familial hypercholestrolemia.
LDL receptor def
infant. failure to thrive, steatorrhea, ancanthocytosis, ataxia, night blindness
Abetalipoproteinemia. inability to synthasize lipoproteins due to def in aboB100 or apoB48
