Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
23 Cards in this Set
- Front
- Back
- 3rd side (hint)
oxaloacetate transaminated-->
|
aspartate
|
|
|
aspartate transaminated -->
|
oxaloacetate
|
|
|
glucokinase vs hexokinase
|
(both key regulatory enzymes in glycolysis); gluc--only in liver, high Km (low affinity)--> v active after meal, induced when insulin high; hex--in ~all tissues, low Km (high affinity) so works even when [glucose ] low. feedback inhib by G6P
|
|
|
regulators of PFK-1
|
(rate limiting step in glycolysis); neg--ATP, citrate; pos--AMP, F2,6BP
|
|
|
regulators of pyruvate kinase
|
(PEP->pyruvate); neg--alanine, ATP; pos--F1,6BP
|
None
|
|
regulators of pyruvate DH
|
(pyruvate->acetyl CoA); neg--ATP, NADH, acetyl CoA
|
|
|
why can alcohol cause hypoglycemia?
|
metabolism of alchohol causes increased NADH...which inhibits gluconeogenesis
|
|
|
thiamine deficiency effect on TCA cycle?
|
thiamine needed for pyruvate DH and alpha KG DH. therefore, TCA slows, get lactic acidosis
|
|
|
why are glycolytic enzyme deficiencies assoc'd with hemolytic anemia?
|
RBCs can only metabolize glucose anaerobically. so if def--> no ATP
|
|
|
cofactors needed for pyruvate DH (and alpha KG DH)
|
pyrophosphate (B1, TPP); FAD (B2); NAD (B3); CoA (B5); lipoic acid
|
|
|
significance of As?
|
inhibits lipoic acid (cofactor for pyruvate DH, alpha KG DH); get vomiting, rice water poo, garlic breath
|
|
|
significance of Cori cycle
|
transfers excess reducing equivalents from RBCs/mm to liver, allowing muscle to function anaerobically and shifting net metabolic burden to liver; net 2ATP.
|
|
|
treatment of pyruvate DH def?
|
increase intake of KETOgenic amino acids (eat a lot of fat and/or lotsa lysine, leucine)
|
|
|
which stress hormones promote gluconeogenesis
|
glucagon, epinephrine, GH, glucocorticoids
|
|
|
where is glucose 6 phosphatase?
|
(G6P->G); in ER of liver, kidney, intestinal epithelium
|
|
|
where are the key regulatory (irreversible) enzymes of gluconeogenesis (4)
|
pyruvate carboxylase-in mit; PEP CK--cyt; F1,6BPase--cyt; G6Pase--cyt
|
|
|
specific requirements of irreversible gluconeogenesis enyzmes
|
PC--ATP, biotin; PEP CK--GTP
|
|
|
products of nonoxidative/reversible reactio of PPP/HMP shunt
|
ribose 5-phophsate (for NT); G3P, F6P (glycolytic intermediates)
|
|
|
absence of galactose-1-phosphate uridyltransferase-->
|
(AR) cataracts, hepatosplenomegaly, MR; due to accumulation of toxic substances (galactitol)
|
|
|
rate limiting step in urea cycle?
|
carbamoyl phosphate synthase I (CO2+ NH4+--> carbamoyl phosphate)
|
|
|
pyruvate transaminated-->
|
alanine
|
|
|
forms of homocystinuria
|
(all AR); 1. cystathione synthase def; 2. dec'd affinity of cystathione synthase for pyridoxal pohsphate (tx: inc. vit B6); 3. methionine synthase def
|
|
|
homocystinuria can cause
|
MR (mental retardation), osteoporosis, tall stature, kyphosis, lens subluxation, atherosclerosis
|
|