Re: How many protons required for ATPase-pump

Hi there!
	I assume you are talking about the ATP synthase enzyme found on the 
inner membrane of mitochondria. This enzyme constitutes about 15% of total 
inner membrane protein. It is a highly conserved molecule. This means not 
only is it similar between plants and animals but it is even very similar 
between mitochondria and chloroplasts. This protein is very old in 
evolutionary terms as well because it is also found in bacteria. To answer 
your other question, it is not known with any certainty how many H+ ions 
are needed to make each molecule of ATP. A standard assumption based on 
energy calculations suggests that 3 H+ must be driven through the membrane 
to synthesize one ATP molecule. Of course, depending on the energy status 
of the cell, the process can reverse itself and pump protons out of the 
inner membrane resulting in production of ADP from ATP.