Lecture 9 Cont. Flashcards
Describe the A subunit of the FO part ATP synthase.
It has two half channels that allow protons to move from the P side to the N side somehow making it’s way through both half channels.
Describe the C subunit of FO ATP synthase.
The C subunit of Fo ATP synthase is the c ring. It can range from 8 to 15 subunits.
It has an acidic amino acid that is theorized to pull the H+ proton from one half channel to the next half channel in the A subunit.
A 360 degree turn will make how many ATPs?
3
TRUE or FLASE: If the c ring is 9 subunits, it take 9 protons to make a 360 degree turn.
TRUE.
And a 120 degree turn will make 1 ATP.
This means it take 3 protons to make 1 ATP. But it really takes 4 total protons including the proton used to pump Pi which is negative against the electrochemical gradient.
What would be the P/O ratios for NADH and FADH2 if the c-ring were made of 15 subunits?
It takes 5 protons (+1) to make ATP.
NADH moves 10 protons. 10/6= 1.67 ATP/NADH
FADH2 moves 6 protons = 1 ATP/FADH2.
The more subunits in a c ring make it less efficient.
TRUE or FALSE: For every two electrons that enter complex 3, 1 of the electrons is recycled in the Q cycle.
True.
