First Aid Biochem Flashcards
apolipoproteins
chylomicron has all but B100
LDL has only B100
HDL has EAC “east australian current”
IDL has E, b100 “eee, 1111, iiii”
VLDL has EC b100 “ez $100”
remnant has E.B. 48 “remains 40 yo EB White”
Hyper-chylomicronemia (type 1)
AR
lipoprotein lipase or CII defect
no increased risk of atherosclerosis
Familial hypercholesterolemia
corneal arcus
tendon xanthomas
AD defect LDL-R
AA has 700 mg/dL, Aa has 300 mg/dL
vitamin D synthesis requires
cholesterol
HMG CoA reductase function
HMG CoA to mevalonate
statins inhibit competitively and reversibly
gluconeogenesis sources
lactate
alanine
glycerol
propionyl-CoA
FAS
citrate shuttle from mitochondrial matrix to cytoplasm for FAS using ATP citrate lyase (acetyl CoA), add biotin CO2 (malonyl CoA), then make palmitate
in liver, mammary lactating, adipose
LCFA degradation
Fatty acid CoA synthase
needs carnitine shuttle INTO mitochondrial matrix, inhibited by malonyl CoA
then B oxidation via acyl-CoA-dehydrogenases to acyl CoA
acyl CoA to both ketones and TCA cycle
medium chain acyl-CoA deficiency
systemic primary carnitine deficiency
AR, accumulate 8-10 C acyl-carnitines, get hypoketotic hypolycemia. Young child with vomiting, seizures, liver dysfunction. Minor illness causes death. Avoid fasting!
can’t transport LCFA into mitochondria. Toxic accumulation. Weakness, hypotonia, and hypoketotic hypoglycemia.
shunting toward ketone bodies
prolonged starvation, DKA lose OAA to gluconeogenesis
Alcoholism excess NADH leads to OAA becoming malate
both cause excess acetyl-CoA
XR lysosomal storage disease
Fabry disease and Hunter syndrome
aseptic necrosis of femur, pancytopenia, megaly, bone crisis, osteoporosis
Gaucher disease
onion skinning lysosomes, no hepatosplenomegaly
Tay Sachs
optic atrophy, globoid cells
Krabbe disease
dementia, ataxia lysosomal storage disease
metachromatic leukodystrophy
gargoylism, airway obstruction
Hurler Syndrome
accumulated cerebroside sulfate
metachromatic leukodystrophy
accumulated galactocerebroside
Krabbe disease
Deficient iduronate sulfatase
Hunter syndrome
Deficient a-L-iduronidase
Hurler syndrome
Deficient B-glucosidase
Gaucher disease
Deficient glucocerebrosidase
Gaucher disease
Deficient glucoce-6-phosphatase
Von Gierke disease
Deficient a-1,4-glucosidase
Deficient a-1,6-glucosidase
Pompe disease
Cori disease
Glycogen storage disease treated with B6
McArdle disease
Glycogen storage disease where must avoid fructose, galactose
Von Gierke disease
Glycogen storage disease with arrhythmias
McArdle disease, from electrolyte abnormalities
Debranching enzyme works on…
parts are…
limit dextrin = 1 to 4 residues left from glycogen phosphorylase
4-a-D-glucanotransferase
a-1,6-glucosidase
Cystinuria
COLA in PCT, gut
treatment is potassium citrate, acetazolamide to alkalinize urine, penicillamine to chelate, hydration
urinary cyanide-nitroprusside test is diagnostic
Causes of homocystinuria
Cystathione synthase deficiency (Tx less Met, more Cys, B12, folate)
Lack of affinity of CS for B6 (Tx in B6 and Cys)
Homocysteine methyltransferase deficiency, uses B12! (Tx increase Met)
maternal PKU
causes congenital heart defects
mental, growth retardation
maple syrup urine disease treatment
thiamine supplement
avoid Ile, Val, Leu
Neonate with poorly regulated respiration and temperature, delays
Carbamoyl phosphate synthetase I deficiency or cofactor N-acetylglutamate synthase deficiency (has hyperammonemia)
Hyperammonemia treatment
lactulose to acidify GI tract
rifaximin to decrease colonic bacterial production
benzoate or phenylbutyrate to bind AA
excess NH4 depletes
a-ketoglutarate, inhibiting TCA cycle
N’s in urea
NH3 and aspartate
Cahill cycle
Alanine from muscle to liver becomes pyruvate via a-KG to Glu to urea, then pyruvate to glucose
Glucose back to muscle
aldose reductase
glucose to sorbitol
galactose to galactitol
requires NADPH
need sorbitol dehydrogenase to convert sorbitol to fructose, but missing in Scwann cells, retina, kidney, and low in lens
glucogenic amino acids
Met, Val, His
Fructose intolerance
aldolase B deficiency accumulating F1P
inhibits glycogenolysis and gluconeogenesis from P deficiency
hypoglycemia, jaundice, cirrhosis, vomiting
Classic galactosemia
can get infantile E coli sepsis
absent galactose-1-P uridyltransferase, which takes UDP from Glu, regenerates via 4-epimerase
pyruvate carboxylase location
mitochondria
activated by acetyl-CoA
glucose-6-phosphatase location
ER
PEPCK requires
GTP
Stimulates fructose-1,6-bisphosphatase
high citrate
low F2,6bisP
muscle lacks
glucose-6-phosphatase
TCA cycle makes per 1 acetyl CoA
3 NADH 1 FADH2 2 CO2 1 GTP = 10 ATP
pyruvate carboxylase
pyruvate to OAA
needs CO2, ATP
increased serum alanine in infant, lactic acidosis, neuro defects
pyruvate dehyrogenase complex deficiency
give fat, lysine, leucine
hexokinase, glucokinase regulation
G6P inhibits hexokinase
F6P inhibits glucokinase
glucokinase Vmax and Km
both higher
faster, less affinity
TPP carries
aldehydes
Arsenic
glycolysis makes 0 net ATP
inhibits lipoic acid
RLS of TCA cycle
isocitrate dehydrogenase
ADP +
ATP -
NADH -
CPS II regulation
UTP -
ATP +
citrate regulatory
inhibits PFK1
stimulates acetyl-CoA carboxylase
FA oxidation RLS
Carnitine acyltransferase 1
Malonyl CoA -
In mitochondria
B oxidation - acetyl CoA production
TCA cycle - oxidative phosphorylation
ketogenesis
Etiology of alcoholic fatty liver
DHAP + NADH –> Glycerol-3-P, which makes TAG with FA
high NADH disfavors TCA, leads to acetyl-CoA excess
vitamin K dependant
2,7,9,10
“1972”
and C, S
Vitamin deficiency causing less adult hair, loss of taste, loss of smell
zinc
Vitamin excess precipitates calcium oxalate nephrolithiasis
vitamin C
also can cause Fe toxicity