Questions about oxidative phosphorylation?

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In summary, uncouplers of oxidative phosphorylation disrupt the proton gradient and make respiration uncontrolled, and 2,4 DNP is an example of an uncoupler. Electrons are not transported as H atoms in the electron transport chain, and ubiquinone and ubiquinol are both mobile electron carriers.
  • #1
sameeralord
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Hello everyone,

This is an area I don't understand much, so I have some questions.

*Uncouplers of oxidative phosphorylation (these are true/false questions)
-make respiration uncontrolled
(I know it is true an it has something to do with ADP no longer controling respiration , but I really don't understand the question much)
-Increase the permeability of the inner mitochondrial membrane to proteins
(I'm thinking true. Is this how they disspiate the hydrogen gradient)
-Increase respiratory rate (Don't know)

Also how does 2,4 DNP acts, does it inihibit a complex, or move hydrogen ions disturbing the gradient?

Also more questions
-Electrons can be transported as H atoms in the electron transport chain?
(I'm assuming false, as it the energy from electrons used to push Hydrogen ions out)
-Ubiquionene is a mobile electron carrier.
(But isn't ubiquinol the reduced form that acts as the carrier)

Thanks a lot :smile:
 
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  • #2
Uncouplers of oxidative phosphorylation make respiration uncontrolled by dissipating the proton gradient, thus bypassing ATP synthase and making ADP no longer control respiration. This is true. Uncouplers also increase the permeability of the inner mitochondrial membrane to proteins, which helps them to dissipate the proton gradient. This is also true. Uncouplers do not necessarily increase respiratory rate; this depends on the state of the electron transport chain and a variety of other factors. 2,4 DNP acts as an uncoupler, by increasing the permeability of the inner mitochondrial membrane to protons. This disrupts the proton gradient, decreasing the efficiency of oxidative phosphorylation, and releasing more energy as heat instead of as ATP. Electrons are not transported as H atoms in the electron transport chain; they are transferred between electron carriers as electrons. Ubiquinone (also known as coenzyme Q) is indeed a mobile electron carrier that shuttles electrons between complexes I, II and III in the electron transport chain. Ubiquinol (the reduced form of ubiquinone) is also a mobile electron carrier, but it is used in complex III.
 

What is oxidative phosphorylation?

Oxidative phosphorylation is a process that occurs in the mitochondria of cells, where energy is produced by converting nutrients into ATP (adenosine triphosphate), the main energy currency of cells. This process involves a series of chemical reactions that use oxygen to break down glucose and other molecules, releasing energy that is used to produce ATP.

How is oxidative phosphorylation different from glycolysis?

Glycolysis is the initial step in cellular respiration that breaks down glucose into smaller molecules and produces a small amount of ATP. Oxidative phosphorylation, on the other hand, is the final step in cellular respiration that uses the products of glycolysis to produce a larger amount of ATP through the electron transport chain and chemiosmosis.

Why is oxygen necessary for oxidative phosphorylation to occur?

Oxygen is necessary for oxidative phosphorylation because it serves as the final electron acceptor in the electron transport chain. Without oxygen, the electron transport chain cannot continue, and ATP cannot be produced through oxidative phosphorylation.

What is the role of mitochondria in oxidative phosphorylation?

Mitochondria are the organelles where oxidative phosphorylation occurs. They contain the enzymes and proteins necessary for the electron transport chain and ATP synthase to function. Mitochondria also have a double membrane structure that allows for the separation of protons and the generation of a proton gradient, which is essential for chemiosmosis and ATP production.

What happens to the energy released during oxidative phosphorylation?

The energy released during oxidative phosphorylation is used to produce ATP, which is then used as the main energy source for cellular processes. Any excess energy is stored in the form of ATP or other molecules for later use. This process is vital for sustaining life and providing the energy needed for various biological functions.

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