Final: citric acid cycle/TCA cycle/Krebs cycle Flashcards
What kind of process do cells need to generate ATP?
a process that generates electricity in the mitochondria
How do we create electricity?
electron-rich molecules must transfer electrons to chain of complexes (electron transport chain)
what is the final electron acceptor in ETC?
oxygen!
electron donor molecules (2)
NADH
FADH2
how do we produce NADH and FADH2?
dehydrogenase enzymes!
in the citric acid cycle (Krebs cycle)
CAC overview
8 rxns
acetyl-coa –> CO2
oxidation of pyruvate to CO2
starving state (what is our source of acetyl-coa and what are hormone levels like)
increase in glucagon, epinephrine, and cortisol
fatty acids are source of acetyl-coa
fed state (what is our source of acetyl-coa and what are hormone levels like)
increase in insulin
have plenty of acetyl-coa from breaking down glucose (mainly), fructose, and galactose
in the liver (source of acetyl-coa?)
alcohol!
external sources of acetyl-coA?
proteins
CAC starting with glucose
1) glycolysis converts 1 glucose to 2 pyruvate
2) 2 pyruvate enter mitochondria
3) pyruvate dehydrogenase makes acetyl-CoA, CO2, and NADH (from NAD+)
*this links glycolysis and CAC
what inhibits isocitrate dehydrogenase
high ATP and high NADH inhibit isocitrate dehydrogenase
what stimulates isocitrate dehydrogenase
high ADP stimulates isocitrate dehydrogenase because it tells the cell more energy is needed
high Ca2+ levels (calcium rises during work, work requires energy)
rate-limiting step of CAC
isocitrate dehydrogenase step!
what can disrupt CAC?
vitamin deficiency
