Oxidative Phosphorylation Flashcards
What can Phosphoryl transfer potential be measured by?
free energy change for the hydrolysis of ATP
What is the standard redox potential?
a measure for how readily X donates an electron (in comparison with H2)
What does a negative redox potential mean?
that the reduced form of X has a lower affinity for electrons than H2
What are the 2 stages of oxidative phosphorylation?
electron transport
ATP synthesis
What occurs in electron transport?
electrons flow from NADH and FADH2 to O2
respiratory chain
energy is used to pump H+ out of the mitochondrial matrix
What occurs in ATP synthesis?
electrochemical gradient of H+ across mitochondrial inner membrane
energy stored in this gradient can be used to synthesise ATP
Are the two stages catalysed by the same or different proton pumps?
different
Electrons from what enter complex 1?
NADH
Electrons from what enter complex 2?
FADH2
Is complex 2 part of TCA?
Yes
What are cytochromes?
proteins which contain a haem group as a functional co-factor
How many of the 4 respiratory complexes pump hydrogen?
3 (complex 2 does not)
Are there more protons in intermembrane space or in matrix?
intermembrane space
What inhibits transfer of electrons to O2?
Cyanide, azide, and CO
Describe non-shivering thermogenesis.
maintains body temperature in
hibernating animals
newborn animals
cold-adapted mammals
brown adipose tissue contains uncoupling protein (UCP) = thermogenin
‘generates heat by short-circuiting the mitochondrial battery’
