21 Questions
What is the primary function of oxidative phosphorylation?
Using energy from oxidation of NADH and FAD2H to synthesize ATP
What is the energy source used by the electron transport system in oxidative phosphorylation?
NADH and FAD2H
What is the primary function of uncoupling proteins (UCPs) in brown adipose tissue?
To generate heat by dissipating the proton-motive force
In which stage of catabolism does oxidative phosphorylation occur?
Stage 4
What happens by the end of the TCA cycle in relation to carbon atoms?
All C-C bonds are broken
What is the role of NADH and FAD2H in the electron transport chain?
They are produced as a result of fatty acid oxidation and drive the electron transport chain, increasing the proton-motive force.
What is the effect of inhibitors of the electron transport chain, such as carbon monoxide and cyanide?
They prevent the oxidation of NADH and FAD2H, leading to a lack of proton-motive force and ATP synthesis.
What is the role of electrons in NADH and FAD2H during oxidative phosphorylation?
Release free energy when transferred to oxygen
How does noradrenaline (norepinephrine) affect the function of brown adipose tissue?
Noradrenaline stimulates lipolysis and the release of fatty acids, and also activates uncoupling proteins to dissipate the proton-motive force as heat.
Which part of the mitochondrion is involved in ATP synthesis during oxidative phosphorylation?
Inner mitochondrial membrane
What is the consequence of the lack of a proton-motive force due to inhibition of the electron transport chain?
ATP cannot be synthesized, and no heat is generated, leading to rapid and irreversible cell damage.
Which of the following complexes in the electron transport chain does not act as a proton translocation complex?
Complex II (Succinate-Q reductase)
What is the main purpose of the proton motive force (PMF) generated during electron transport?
To drive the synthesis of ATP from ADP and Pi
What is the approximate amount of ATP synthesized per 2 moles of NADH oxidized?
5 moles of ATP
What is the main function of uncoupling proteins (UCPs) in the inner mitochondrial membrane?
To increase the permeability of the membrane to protons
How does the concentration of ATP in the mitochondrial matrix affect the rate of electron transport and ATP synthesis?
High ATP concentration decreases electron transport and ATP synthesis
Which complex in the electron transport chain oxidizes FADH2 and transfers electrons to coenzyme Q?
Complex II (Succinate-Q reductase)
What is the primary role of coenzyme Q (ubiquinone) in the electron transport chain?
To transfer electrons from Complex II to Complex III
What is the main purpose of the proton leak through uncoupling proteins (UCPs) in the inner mitochondrial membrane?
To increase the production of heat
Which complex in the electron transport chain passes the electrons to cytochrome c?
Complex III (Q-cytochrome c oxidoreductase)
What is the primary role of Complex IV (Cytochrome c oxidase) in the electron transport chain?
To pass the electrons from cytochrome c to molecular oxygen
Test your knowledge about the process of oxidative phosphorylation where the free energy of oxidation of NADH and FAD2H is used to synthesize ATP. Learn about its key features and how it is related to glucose oxidation and the TCA cycle.
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