An underground stream with a K concentration of 2M and a pH

An underground stream with a K+ concentration of 2M and a pH of 3 is found and a microbe is isolated from it. You measure the internal K+ concentration and discover that it has a K+ of 360mM. When placed in conditions that stimulate chemistry of stream, with valinomycin added, the cells make ATP. It could be possible that the cells use a proton motive force to produce ATP via membrane bound ATPase.

a) Calculate the expected internal pH of the cells in order for them to generate a P of about -180mV under the conditions described.

b) If the external pH is changed to 8.0 what concentration of external K+ will yield a deltaP of about -180mV.
Remember log(x/y)=log(x)-log(y)

c) On the membrane below, show the movement of a proton that results in delta pH

cytoplasm [ ] periplasmic space
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Solution

Lowest is the Molarity then pH will be heighest.

K+ Molar concentration is 2M and pH 3

After cell absorption the molar concentration found inside cell evaluated 360mM. Converting to Molar form it becomes 0.36M

Change in Molar concentration (2-0.36) = 1.64M . So decrease in molarity is1.64M. which is equal to 82 % decrease in Molarity.It means there will be 82% Increase in pH 3.54