Name: Saad H.
Status: Student
Age: 16
Location: N/A
Country: N/A
Date: September 2002
Question:
I do not quite understand the significance of membranes
in the biochemical events which occur in mitochondria and chloroplasts.
Your explanation would be much appreciated.
Replies:
The membranes of these organelles are essential to their biological
function! Both mitochondria and chloroplasts convert energy into ATP, the
cell's short-term energy storage molecule. They do this by first using the
energy to create a H+ concentration difference across a barrier (membrane).
Then, they harness the natural flow of H+ from the side of greater
concentration to the side of lower concentration by coupling it to ATP
synthesis. Exactly how this is accomplished is still the subject of
vigorous and fascinating research. I predict that several more Nobel prizes
will be awarded to researchers in the field by the time it is understood.
But this ATP synthesis could not be powered by the concentration difference
unless the membrane is there to keep the two parts (inside and outside)
separated!
Richard E. Barrans Jr., Ph.D.
Director of Academic Programs
PG Research Foundation, Darien, Illinois
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