respiration question

[polarmolar]

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What donates the H+ that accumulates in the intermembrane space in the mitochondria?

 

[nitrolegs]

What donates the H+ that accumulates in the intermembrane space in the mitochondria?

if i were to guess...NADH and FADH2

 

[polarmolar]

if i were to guess...NADH and FADH2

Thats what I was thinking also. Cliffs doesn't mention specifically, and I was thinking I would probably get a question asking just this lol.

 

[doc3232]

if i were to guess...NADH and FADH2

I don't think so...that wouldn't be enough hydrogens.
Water naturally dissociates into H+ and OH- so normally there are 10^-7 Molar Hydrogen concentration. This a never ending supply of hydrogens as long as there is water in the mitochondria (which there always is).

 

[Albuterol]

These NADH's take their electrons (and energy) to the ETC, specifically to Complex I of the ETC. The electrons (there are two electrons carried by each NADH) are transferred to an electron acceptor on Complex I and an NAD is regenerated as the NADH gives up its electrons. The NAD can now go back to the Krebs Cycle to pick up another pair of electrons. The electrons that were donated to Complex I now pass through series of proteins within the complex. Each time that the electrons are transferred, they lose some of the energy that they originally contained when with the NADH. (This is somewhat similar to a ball bouncing down steps, as it moves down, he amount of energy in the ball decreases and unless some energy is added to the ball, it will not go up the stairs). The energy that is released as the electrons pass through the electron carriers in Complex I is utilized to pump hydrogen ions (protons) across the inner mitochondrial membrane

i didnt write this..found it somewhere.
http://www2.austin.cc.tx.us/~emeyerth/electrontrans.htm

 

[Doa110]

I don't think so...that wouldn't be enough hydrogens.
Water naturally dissociates into H+ and OH- so normally there are 10^-7 Molar Hydrogen concentration. This a never ending supply of hydrogens as long as there is water in the mitochondria (which there always is).

In cellular respiration water molecule is formed at the end of ETC when O2 accepts the electrons. In PSI&II is where H2O splits, but even then the H+ will go to NADP+ to make NADPH (in non-cyclic). The whole point of H+ gradient in cellular respiration is to relaese energy, so that energy in turn could be used to generate ATP. We also know that NADH and FADH2 are the source of energy for ETC. So I would say it comes from NADH and FADH2.

 

[IWantSmile]

In cellular respiration water molecule is formed at the end of ETC when O2 accepts the electrons. In PSI&II is where H2O splits, but even then the H+ will go to NADP+ to make NADPH (in non-cyclic). The whole point of H+ gradient in cellular respiration is to relaese energy, so that energy in turn could be used to generate ATP. We also know that NADH and FADH2 are the source of energy for ETC. So I would say it comes from NADH and FADH2.

I think so too.

 

[doc3232]

the H's that add onto NAD to form NADH during Krebs come from within the mitochondria.
Also, most importantly the Hydrogens are constantly reentering the matrix through ATPases. So it is a like a cycle.