Biochemistry Chapter 11: Oxidative Phosphorylation

Flashcards covering key concepts from Chapter 11 on oxidative phosphorylation and related mitochondrial processes.

What theory explains energy conversion in mitochondria by establishing a proton gradient?

Chemiosmotic Theory.

What is established across the mitochondrial inner membrane, leading to ATP production?

A proton (H+) gradient.

What is the primary role of the ATP synthase complex in mitochondria?

ATP synthesis by utilizing the inward flow of protons.

What are the four complexes involved in the mitochondrial electron transport system?

Complex I: NADH–ubiquinone oxidoreductase, Complex II: Succinate dehydrogenase, Complex III: Ubiquinone-cytochrome c oxidoreductase, Complex IV: Cytochrome c oxidase.

What is the final electron acceptor in the electron transport chain?

Oxygen (O2), which is reduced to form water (H2O).

What substances inhibit the electron transport system?

Rotenone, Hydrogen cyanide, Carbon monoxide, Antimycin A.

What is the net reaction for NADH oxidation in oxidative phosphorylation?

2 NADH + 2 H+ + 5 ADP + 5 Pi + O2 → 2 NAD+ + 5 ATP + 2 H2O.

What two components make up the ATP synthase complex?

F1 (catalytic activity) and Fo (proton channel).

What is the importance of the Q cycle in complex III?

It converts the 2-electron transfer process into two 1-electron transfers.

How does proton uncoupling affect ATP synthesis?

It reduces ATP synthesis by causing leakage of protons and instead produces heat.

What is the purpose of the phosphate translocase in mitochondria?

It facilitates the import of inorganic phosphate into the mitochondrial matrix.

How does ADP regulate oxidative phosphorylation?

High levels of ADP stimulate aerobic respiration, while high ATP levels inhibit it.