Mitochondrial resp chain Flashcards
What is the name of complex 1 in the etc and what happens here?
NADH dehydrogenase, electrons are accepted from NADH and the energy is harnessed to move 4H+ into the intramembrane space
What Is FMN
a compound in complex 1 which initially accepts H from NADH and becomes FMNH2
What is the enzyme that composes complex 2
Succinate dehydrogenase, this is where electrons from FADH2 are received and Complex 2 passes them to ubiquinone
What is the function of complex 3 and what role does cytochrome c play
to accept electrons from ubiquinone, cytochrome c then passes these electrons from complex 3 to complex 4
which of the 4 complexes isn’t a proton pump
complex 2 isn’t a proton pump
what is the role of adenine nucleotide translocase
known as an antiporter, exchanges ATP (4-) for ADP in the intramembrane space (3-) the more negative ATP is favoured by the gradient created from the proton pumps.
What is the role of phosphate translocase
Known as a symporter, brings protons and phosphate into the matrix from the intramembrane space to provide a source of phosphate ions for ADP to create ATP
Describe the structure of ATP synthase
It is an F-type ATPase with two functional domains:
- F0, an oligomycin sensitive proton channel
- F1, an ATP synthase
How many types of subunits are there in F0
There are 3 different types of subunits: a,b and c
how many types of subunits comprise F1
5 different types, use greek letters, alpha to epsilon
How many of each subunit are there in F1
3 alpha, 3 betas, 1 gamma, 1 delta and 1 epsilon, together with forms a complex of 9 subunits where the 3 beta subunits do most of the work.
Describe the theory of rotational catalysis
The gamma subunit interacts with a beta subunit to release ATP while the other 2 subunits are in different states where one is forming ATP and one has just had ATP bind to it. The gamma subunit rotates and interacts with each one to release ATP separately and at any one time, the 3 subunits are in different states.
How does the gamma subunit rotate to bring about rotational catalysis
The c10 subunit rotates when protons move through which causes the gamma subunit attached to move also.
What is the role of an uncoupling reagent
To dissipate the pH gradients by transporting protons back into the matrix of the mitochondria and the energy is released as heat
Give a natural example of uncoupling
Therminogen is found in brown adipose tissue and has a specific proton channel via which the proton gradient may be dissipated, the energy released as heat, important in new-borns and hibernating mammals.
