Oxidative Phosphorylation P1

What is the energy release when ATP converts to ADP and Pi?

-7.3 kcal/mol

How much ATP does an adult body contain at any time?

Approximately 100g of ATP.

What is the primary role of ATP in cells?

ATP serves as the immediate source of energy.

How is ATP generated in cells?

By coupling the transfer of high-energy electrons from food to the phosphorylation of ADP.

Approximately how many ATP molecules does one glucose produce?

About 30 ATP molecules.

What are the sources of ATP production from glucose?

26 via oxidative phosphorylation, 2 from glycolysis, and 2 from the TCA cycle.

What is the function of oxygen in cellular respiration?

Oxygen acts as the terminal electron acceptor.

What is the main challenge in electron transfer to O₂?

To safely and gradually transfer electrons to O₂ without causing cellular damage.

Where is the Electron Transport Chain (ETC) located?

On the inner mitochondrial membrane.

What happens to electrons as they pass through the ETC?

They pass through a series of carriers with increasing redox potential, releasing energy stepwise.

What is the role of the energy released in the electron transport chain?

It is used to pump protons into the intermembrane space.

What is redox potential?

The tendency of a molecule to acquire electrons; electrons flow from low to high redox potential.

What does a ΔE of +1.14 V indicate about energy production?

It corresponds to a ΔG of -220 kJ/mol, indicating energy is available for work.

What does the Chemiosmotic Theory state?

The proton motive force generated by proton pumping drives ATP synthesis.

Who proposed the Chemiosmotic Theory?

Peter Mitchell.

What is the outer membrane of the mitochondrion like?

It is permeable.

What is the function of cristae in mitochondria?

They increase the surface area for the Electron Transport Chain.

What are the compartments of the mitochondrion?

The matrix and the intermembrane space.

What occurs in the mitochondrial matrix?

Enzymes of the TCA cycle and fatty acid oxidation.

What is Complex I of the ETC known as?

NADH:Q oxidoreductase.

What does Complex II of the ETC do?

No proton pumping occurs here; it transfers electrons from succinate to FADH₂.

What is the Q Pool in the ETC?

A mobile pool of ubiquinone (Q) and ubiquinol (QH₂).

What does Cytochrome c do in the ETC?

It carries electrons between Complex III and Complex IV.

What is the role of Complex IV in the ETC?

It accepts electrons and facilitates the formation of H₂O from O₂.

What are some cofactors involved in the ETC?

FMN, Fe-S clusters, hemes, copper centers, and ubiquinone.

What is the unique lipid found in the inner mitochondrial membrane?

Cardiolipin.

From what kind of ancestor did mitochondria evolve?

An engulfed bacterial ancestor.

What are the biological steps in energy production from food to water?

Food to NADH/FADH₂, to ETC complexes, to proton gradient, to ATP synthesis, to O₂ accepting electrons forming H₂O.

What is the importance of constant ATP regeneration?

Necessary because the body recycles its entire weight in ATP daily.