Glycolysis, TCA cycle, pyruvate, electron transport chain Flashcards
Glycolysis site and all steps (not the enzymes)
Cytoplasm
Glucose –> Glucose-6-P –> Fructose-6-P –>
Fructose-1,6-BP –> Gltceraldehyde-3-P –> 1,3 biphosphoglycerate –> 3-phosphoglycerate –> 2-phosphoglycerate –> phosphoenolpyruvate (PEP)
–> Pyruvate
Glycolysis site
Cytoplasm
Hexokinase regulation
Glucose -6-P -
Glycolysis steps that require ATP
Glucose to 6-P- glucose (hexokinase/glucokinase)
Fructose 6-P to fructose -1,6- BP (phosphofrouktokinase
Glucokinase regulation
Fructose-6-P -
Glucokinase vs hexokinase about location
Glucokinase in liver and β cells of pancreas
Hexokinase in all other tissues
Glycolysis stpes that produce ATP
1,3-Biphosphoglycerate to 3-phosphoglycerate (phosphoglycerate kinase)
Phosphoenolpyruvate to pyruvate (pyruvate kinase)
Glycolysis stpes that produce ATP
1,3-Biphosphoglycerate to 3-phosphoglycerate (phosphoglycerate kinase)
Phosphoenolpyruvate to pyruvate (pyruvate kinase)
Fructose-6-P to fructose-2,6-BP
Phosphofructokinase -2 (activate in fed state)
Fructose -2,6-biphosphate enzymes (and active when)
- Fructose bisphosphate-2 –> active in fasting
2. Phosphofructokinase-2 –> active in fed
Fructose-2,6-BP to fructose-6-P
Fructose bisphosphatase-2 (active in fasting state)
Fructose-2,6-bisphosphate/fasting state
Glucagon –> increased cAMP –> increased protein kinase A –> increased fructose bisphosphatase-2, decreased phosphofuctokinase-2,less glycolysis, more gluconeogenesis
Fructose bisphosphate-2 vs Phosphofructokinase-2 according to action and regulation
Are the same bifunctional enzyme whose function is reversed by phosphorylation
Fructose-2,6-bisphosphate/fed state
Insulin –> decreased cAMP –> decreased protein kinase A –> decreased fructose bisphosphatase-2, increased phosphofuctokinase-2, more glycolysis, less gluconeogenesis
Pyruvate dehydrogenase complex site
What does it link?
MITOCHONDRIAL ENZYME complex linking glycolysis and TCA cycle
Pyruvate dehydrogenase complex regulation
Active in fed state, not in fasting
Pyruvate dehydrogenase complex reaction
Pyruvate + NAD + CoA –> acetyl CoA + CO2 + NADH
Pyruvate dehydrogenase complex contain how many enzymes
3
Pyruvate dehydrogenase complex cofactors
- Pyrophosphate (B1, TPP)
- FAD (riboflavin B2)
- NAD (B3, niacin)
- CoA (B5, pantothenate)
- Lipoic acid
Pyruvate dehydrogenase complex activated in by
- increased NAD+/NADH ratio
- increased ADP
- Increased Ca2+
The Pyruvate dehydrogenase complex is similar to
a-ketoglutarate dehydrogenase complex (same cofactors, similar substrate and action
Lipoic acid inhibitor
Arsenic
a-ketoglutarate dehydrogenase complex converts
a-ketoglutarate –> succinyl-CoA (TCA)
Arsenic acid inhibits lipoic acids. Findings
- Vomiting
- Rice water stools
- Garlic breath
Arsenic action
Inhibit glycolysis
Inhibit lipoic acid (dehydrogenase complex)
Pyruvate dehydrogenase complex deficiency causes
A buildup of pyruvate that gets shunted to lactate (via LDH) and alanine (via ALT)
Glycolysis pathway (mediators)
Glucose glucose-6-P fructose-6-P fructose-1-6-BP glyceraldehyde-3-P 1,3-biphosphoglycerate
2-phosphoglycerate phosphoenolpyruvate –> pyruvate
Pyruvate dehydrogenase complex deficiency treatments
Increased intake of ketogenic nutrients (high fat content or increased lysine and leucine
Pyruvate dehydrogenase complex deficiency findings
- Neurologic defects
- Lactic acidosis
- Serum alanine starting in infancy
Ketogenic amino acid vs glucogenic aminoacid
A ketogenic amino acid is an amino acid that can be degraded directly into acetyl CoA through ketogenesis. This is in contrast to the glucogenic amino acids, which are converted into glucose.