Feb6 M3-Normal and Abnormal Carbohydrate Metabolism - 2 Flashcards
what happens to pyruvate before enters the TCA cycle
converted to acetyl-CoA by pyruvate dehydrogenase (PDH)
input and output of pyruvate to acetyl CoA
input: CoA and NAD
output: NADH and CO2
3 ways conversion of pyruvate to acetyl CoA is regulated
- phosphorylation
- end product inhibition (NADH and acetyl CoA)
- need cofactors (thiamine and lipoic acid)
PDH abnormalities common where
in cancer. because of Warburg effect (PDH activity is suppressed)
genetic PDH deficiency: name of disease
Leigh’s syndrome
(in PDH deficiencies) Leigh’s syndrome what population + blood test + symptoms
in children. high lactate and pyruvate (chronic lactic acidosis). severe neuro defects. lethal.
(in PDH deficiencies): thamine deficiency: name of disease
Wernicke-Korsokoff syndrome
Wernicke-Korsokoff syndrome symptoms + one possible cause
encephalopathy and psychosis
possible cause: alcoholic (low thiamine uptake + poor thiamine processing bc of lactic acidosis)
toxic PDH deficiency and pathophgy (+main prob is where)
arsenic toxicity. binds lipoic acid, blocking this cofactor. main prob in CNS bc need glucose
useful products generated in Kreb’s cycle
NADH, FADH2, GTP
how TCA cycle starts and why CO2 made
start with 2C acetyl-CoA. combines with oxaloacetate (4C) to make citrate (6C). 2C losts on the way in 2 CO2
most common TCA deficiency
don’t exist. incompatible with life
energy released produced in whole ETC and how much serves to make ATP
-53 Kcal per mol
+22 kcal per mol of ATP made (3 mol ATP bc each is -7.3 kcal per mol)
31 kcal to waste (inefficient system)
protein using H+ gradient IMM to matrix to make ATP
ATP synthase
UCP function
let H+ leak to matrix and energy of the gradient lost to heat
3 ways ETC may stop working
cyanide poisoning (CN)
CO poisoning
Leigh’s syndrome
CN poisoning pathophgy
blocks Fe3+ in complex IV (CNs damage)
