acidity of mitochondrial matrix

[license2kill]

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When cytochromes of the ETC accept hi energy e- from NADH and FADH2 and move them down the energy gradient, protons get moved from the matrix to the intermembrane space, right? So where does the matrix get this supply of protons in the first place? Is it from the byproducts of Kreb's cycle? In my notes, I have that NADH gets formed along with protons when pyruvate turns into acetyl CoA and also when citrate turns into isocitrate. Is it through these interactions leading to "scraps" of protons collecting in the matrix?

Also, when NADH and FADH2 dump the hi energy electrons, it oxidizes NADH and FADH2, what about the protons that are released from this event? Where do they go? Are these protons accumulating in the matrix before being shuttled out into the intermembrane space?

Lastly, if protons are both in the matrix and intermembrane space, then which area is more acidic? I would think that the intermembrane would be more acidic b/c of the build up of protons. Am I wrong?

Thanks.🙂

 

[osimsDDS]

H+ are pumped into the inner-membrane space of the mitochondria...a chemosmotic gradient is acquired and then protons fall back down from the inner-membrane space past the inner-membrane via ATP-synthase and generates ATP...H+ basically is pumped into the inner-membrane space so that means the pH is higher in the matrix and the pH is lower in the inner-membrane space.

In plants tho, in the light reactions H+ ions are pumped inside the thylakoid (also from water being split you get H+ inside the thylakoid space or lumen) and a gradient is aquired between the stroma and the thylakoid lumen...a high pH is on the outside stroma and a low pH on the inside of the thylakoid lumen, then H+ goes down its gradient and ATP-synthase makes ATP from ADP...

In any situation the key here is to understand what your using the ATP for...think about the light reaction, your using the ATP for the dark reactions ultimately which happen in the stroma so you gradient has to be in the thylakoid lumen in order to generate ATP into the stroma!!!!

 

[license2kill]

thx🙂