Metabolism disorders Flashcards
essential fructosuria
no big deal, AR, benign
lack FRUCTOKINASE, but that’s okay because Fructose can get converted to G6P by hexokinase, or you just pee it out
fructose intolerance
deficiency: ALDOLASE B
causes a build up of F-1-P –> depletes usable phosphate –> depletes ability to make ATP –> can’t do gluconeogenesis or glycogenolysis + build of of AMP then gets shunted towards UMP pathway and gets turned into Uric acid
levels of metabolites in fructose intolerance
high F1P, low useable P, high uric acid
essential amino acids
PVT TIM HALL
phenyl, valine, threonine
tryp, isoluec, meth
histidine, arginine, lysine, leucine
aldolase B deficiency
FRUCTOSE metab
uridyltransferance deficiency
GALACTOSE metab
galactokinase deficiency
messed up galactokinase
you get a build up of galactitol –> cataracts, failure to track
classic galactosemia
this is a problem. You lack uridyltransferase –> meaning you can’t metabolize Galactose-1-phosphate –> build up of unusable phosphate products –> leads to decreased gluconeogensis/ glycogenolysis
hartnups
defect of neutral aa transporters in gut and urine
B3 deficiency: pellagra –> diarrhea, dermatitis, dementia
hyperammonia disrupts the _______ cycle in _______ (brain)
glutamine- glutamate cycle, astrocytes
this is due to astrocyte swelling (hyperosmoloartiy), impaired glutamine release
infection seen in classic galactosemia?
e. coli sepsis in neonates
NAD+ is involved in what types of reactions? NADH?
NAD+ = catabolic
NADH= anabolic
NADH is longer, its built up. NAD+ is shorter, its been broken down.
NADH is involved in what specific reactions?
resp burst
anabolic reactions –> FATTY ACID, CHOLESTEROL
cytp450
glutathione reductase
how does the body make glucose during starvation?
glycogenolysis -12-18 hours
then, gluconeogenesis (oxaloacetate –> PEP)
basic steps of gluconeogenesis
Pyruvate –> pyruvate CARBOXYLASE –> oxaloacetate –> pep-ck –> PEP, and then moves on up to glucose
primary carnitine deficiency (mech)
causes hypoketotic hypoglycemia –> defect in beta oxidation of FA
carnitine shuttle is used to shuttle fatty acids from cytoplasm to mitochondria to break down into ketone bodies and go into TCA
signs of primary carnitine deficiency
cardiomyopathy, elevated creatine (weakness, decrease carnitine, NO KETONES + HYPOGLYCEMIA
can you use triglycerides to make glucose?
yes. Glycerol stored in adipose tissue can be broken down by GLYCEROL KINASE to yield DHAP through G3P
how does acetyl co a regulate the fate of pyruvate?
HIGH acetyl co diverts pyruvate to PYRUVATE DECARBOXYLASE for gluconeogenesis
when levels are low, it will upregulate PDH complex in order to keep energy up for cell
hypoketotic hypoglycemia
problem with beta oxidation of fatty acids
what cofactors are represented by the mnemonic “TLC for Nancy”? What reactions are they necessary for?
thiamine (b1), Lipoic acid (inhib by arsenic), Co-A, FAD (b2), NAD (b3)
Pyruvate Dehydrogenase Complex
aKetoglutarate
BCKDC (MSUD) –> supplmenet with THIAMINE!
Biotin (B7) is used as a cofactor for what type of reactions?
Carboxylase reactions
Pyruvate –> oxalo
Acetly CoA –> malonyl (fatty acid synth)
Proionyl CoA –>methylmalonyl
propionic acidemia
lack PROPIONYL COA CARBOXYLASE
converts prpionyl CoA –> methylmalonyl CoA (goes into TCA as succinyl CoA via B12)
val, isoluece, threonine, methionine, odd chain fatty acids enter here
when does propionic acidemia present? how?
presents in the first few weeks of life with lethargy, poor feeding, vomitting
high ketones, hypoglycemia, hypotonia
