Hydrochloric acid (HCL) in the stomach..

[TwinkleK]

Cells in the wall of the mamalian stomach secrete HCL at a concentration of 0.1M.

The secreted -protons, which are derived from the intracellular hydration of CO2 by carbonic anhydrase, are pumped out by an (H+ k+) ATPase antiport transporter is also required to complete the overall transport system.

a) Calculate the pH of the secreted HCL. How does this compare to the cystolic pH of 7.4?

b) Write a reaction catalysed by the carbonic anhydrase enzyme.

c) Draw a diagram to show how the action of both transport proteins results in the secretion of HCL.

d) Explain how a proton pump inhibitor might be effective in the treatment of a stomach ulcer.

Can someone please point me in the right direction? Or just help me out with the first two questions..please?

Thank you:)

[TwinkleK]

Erm, is the answer for question b?

The reaction catalyzed by carbonic anhydrase is:

CO2 + H2O -----(Carbonic anhydrase)-----> HC0-3 + H+
(in tissues - high CO2 concentration)

I'm not sure though..

[JackBean]

a) pH = -log [H+]

b) http://www.chem.qmul.ac.uk/iubmb/enzyme/

[TwinkleK]

Thanks..

a) Is this like a standard equation? Where do I put my equations in??

b) Sorry, but I am not getting this at all..

[JackBean]

a) what equations do you want put into where?

b) you got link, where you can search for enzymes. Look for anhydrase and first link is the one you're looking for. There will you find the equation.

[TwinkleK]

a) how do I use the formula "pH = log10 [H+]"

I can't do this because I don't have the [H+] and I can't rearrange it to find to: "[H+] = log10 pH"


Becuase I don't have the pH, ony the information as given in the question....

[canalon]

Yes you have all the information, and you are right you can say that [H+]= - log10 pH because the invert relation to a log is not another log. But then your problem is that you can't do math.
The thing is [H+]= 10^(- pH)

[JackBean]

where does the H+ come from?

[TwinkleK]

Well it's the amoount of hydrogen ions isn't it?

[JackBean]

no, it's concentration. And that's not what I asked for.