Electron Transport Chain Flashcards
What is the main point regarding the electron transport chain?
The transport of electrons from NADH to O2 is a multi-step process and coupled to ATP formation (oxidative phosphorylation)
Inside the inner mitochondrial membrane, what is the environment like?
high pH (basic) low [H+]
In the inner membrane space (between the inner mitochondrial membrane and the outer mitochondrial membrane), what is the environment like?
low pH (acidic) high [H+]
What are the cofactors at complex 1?
NADH + H+ —> NAD+
How many protons cross the IMM at complex 1?
4 H+
What are the cofactors at complex 2?
- succinate is converted to fumarate
- FAD is converted into FADH2
How many protons cross the IMM at complex 2?
none
What are the cofactors at complex 3?
Well electrons from UQH2 –> UQ get transported through complex 3 and then head to cytochrome c and then enter complex 4
How many protons cross the IMM at complex 3?
4 H+
What are the cofactors at complex 4?
1/2O2 + 2H+ –> H20
How many protons cross the IMM at complex 4?
2 H+
Next there is ATP synthesis driven by proton-motive force which transports the 10H+ from the inter membrane space into the matrix. How many ATP molecules are produced?
2.5 ATP
4H+/ATP
Next there is ATP synthesis driven by proton-motive force which transports the 10H+ from the inter membrane space into the matrix. What co factors drive this pump?
ADP + Pi –> ATP
What conditions drive the ATP synthesis?
- chemical potential inside is alkaline
- electric potential inside is negative
What formula is associated with ETC?
deltaG = -nFdeltaE’°
What does NAD stand for?
Nicotinamide Adenine Dinucleotide
How does electrons flow through the ETC?
Carriers with high negative reduction potentials (E’°) pass electrons to carries with high positive reduction potentials.
Describe complex 1
NADH dehydrogenase, FMN flavoprotein + FeS, CoQ (ubiquinone)
Describe complex 2
Succinate dehydrogenase
Describe complex 3
cytochrome b + c1 + 11 proteins
Describe complex 4
cytochrome oxidase (a + a3 + 13 proteins)
Describe the transfer of electrons in complex 1
NADH to CoQ
Describe the transfer of electrons in complex 2
succinate dehydrogenase with FAD transfers e- to CoQ
Describe the transfer of electrons in complex 3
CoQ to cyt c
Describe the transfer of electrons in complex 4
cyt c to O2
What is the deltaE’° for ETC
+1.14 volts
What is the deltaG’° for ETC
-220 kJ/mol
After glycolysis how many ATP are made?
7
After pyruvate to acetyl CoA how many ATP are made?
5 (plus 7 from glycolysis gives a total of 12)
How many ATP are made from the citric acid cycle?
20 (plus 12 is a total of 32)
How many ATP total from glycolysis and TCA?
32 ATP
How much energy is in 1 ATP molecule?
976 kJ/mol (34% of 2840kJ/mol available) so that suggests that 65% of the G is conserved
