bioenergetics Flashcards
What is the primary function of mitochondria?
generate ATP through oxidative phosphorylation, providing energy for cellular processes.
where does the TCA cycle take place
mitochondrial matrix
where does oxidative phosphorylation take place
inner mitochondrial membrane
What is the chemiosmotic theory?
explains how ATP is generated in mitochondria via a proton gradient across the inner mitochondrial membrane
What generates the proton gradient in mitochondria?
electron transport chain
How is oxygen involved in the chemiosmotic process?
the final electron acceptor
What are the mobile electron carriers in the ETC?
Ubiquinone (Coenzyme Q) and cytochrome c
What is the role of Complex I in the ETC?
oxidizes NADH, transfers electrons to ubiquinone, and pumps protons into the intermembrane space
What is the role of Complex II?
oxidizes succinate in the citric acid cycle, transfers electrons to ubiquinone, but does not pump protons.
What is the role of Complex III?
transfers electrons from ubiquinone to cytochrome c and pumps protons across the inner membrane.
What is the role of Complex IV?
transfers electrons from cytochrome c to oxygen (the final electron acceptor), forming water, and pumps protons
What is the primary function of the ETC?
To transfer electrons from NADH and FADH₂ to oxygen, while pumping protons to create a proton gradient that drives ATP synthesis
How does Complex I generate a proton gradient?
pumps protons from matrix to intermembrane space
What is the role of FADH₂ in the ETC?
donates electrons to complex II
Where does ATP synthesis occur in the cell?
inner mitochondrial membrane
What enzyme is responsible for ATP synthesis?
ATP synthase
How does ATP synthase function?
uses the energy from the proton gradient generated by the ETC to rotate and synthesize ATP from ADP and Pi as protons flow through it
What is the proton motive force?
the potential energy stored in the proton gradient
How does the proton motive force power ATP synthase?
Protons flow back into the mitochondrial matrix through the F₀ subunit of ATP synthase, causing the F₁ subunit to rotate and catalyze the synthesis of ATP.
ow many ATP molecules are produced per NADH and FADH₂ during oxidative phosphorylation?
NADH produces about 2.5 ATP molecules, and FADH₂ produces about 1.5 ATP molecules
What is the efficiency of ATP production through the electron transport chain?
34-38 ATP molecules from one glucose molecule during cellular respiration.
