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Topic: Help - Protons translocation in mitochondria?  (Read 2692 times)

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Offline Iamyourfather

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Help - Protons translocation in mitochondria?
« on: November 19, 2012, 09:02:36 PM »
I'm really confused with this and if anyone can help me I'll be very grateful :)

Electron transfer translocates protons from the mitochondrial matrix to the external
medium, establishing a pH gradient across the inner membrane (outside more acidic than
inside). The tendency of protons to diffuse back into the matrix is the driving force for ATP
synthesis by ATP synthase. During oxidative phosphorylation by a suspension of
mitochondria in a medium of pH 7.4, the pH of the matrix has been measured as 7.7.
a) Calculate [H+] in the external medium and in the matrix under these conditions
b) What is the outside-to-inside ratio of [H+]? Comment on the energy inherent in this concentration  difference. 
c) From these data, is the pH gradient alone sufficient to generate ATP? Explain
d) If not, suggest how the necessary energy for synthesis of ATP arises
e) Calculate the number of protons in a respiring liver mitochondrion, assuming its inner
matrix compartment is a sphere of diameter 1.6 µm. 

Offline Dan

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Re: Help - Protons translocation in mitochondria?
« Reply #1 on: November 20, 2012, 03:15:01 AM »
To start, how is pH related to [H+]?
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Offline Babcock_Hall

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Re: Help - Protons translocation in mitochondria?
« Reply #2 on: November 20, 2012, 08:44:54 AM »
Do you know the equation that relates ΔG to a concentration difference across a membrane?

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