Section 1: Structure and Organization
Describe the structure of mitochondria.
Name the enzymes present in mitochondria.
Define mitoplast.
Describe the structural differences between the inner mitochondrial membrane (IMM) and the outer mitochondrial membrane (OMM). How does the protein-to-lipid ratio reflect their functions?
- What is the role of cardiolipin in the inner membrane, and how does its unique structure support the function of the respiratory chain complexes?
- Explain the significance of mitochondrial cristae junctions. How does the shape of the cristae affect the local pH gradient?
How is the intermembrane space (IMS) chemically different from the cytosol, considering the presence of porins in the OMM?
- Define mt DNA.
- What is Cristae mitchondralis?
- Define Subunits of Person & Subunits of Fernandez Moran.
- Briefly describe Mitochondrial membrane.
- What are the function of mitochondris.
Section 2: The Mitochondrial Respiratory Chain (ETC)
- Describe the Q-cycle in Complex III. Why is it necessary for a two-electron carrier (Ubiquinol) to transfer electrons to a one-electron carrier (Cytochrome c)?
- What are the specific prosthetic groups involved in Complex IV (Cytochrome c Oxidase) that allow for the reduction of oxygen to water without releasing reactive oxygen species (ROS)?
- Explain the inhibitory mechanism of Rotenone, Antimycin A, and Cyanide on specific complexes of the ETC.
- Compare and contrast the entry points of electrons from NADH and FADH₂. Why does NADH oxidation result in more ATP than FADH₂?
- Complex II (Succinate Dehydrogenase) is unique in the ETC. Explain its dual role in the TCA cycle and the respiratory chain.
Section 3: Chemiosmotic Hypothesis
- Define the Proton Motive Force ( Δp) and explain its two components: the electrical potential (ΔΨ) and the chemical gradient ( Δ pH).
- How did Peter Mitchell’s Chemiosmotic Hypothesis challenge the previous "chemical intermediate" theory of ATP synthesis?
- What is the effect of uncoupling proteins (UCP1/Thermogenin) on the proton gradient, and what is the physiological outcome in brown adipose tissue?
- If the IMM were to become permeable to protons, how would this affect the rate of oxygen consumption versus the rate of ATP synthesis?
Section 4: ATP Synthase and Oxidative Phosphorylation
- Describe the structural symmetry of the F1 and Fo subunits of ATP Synthase. Which part acts as the "stator" and which as the "rotor"?
- Explain Paul Boyer’s Binding Change Mechanism. Distinguish between the three conformational states of the β subunits: Open (O), Loose (L), and Tight (T).
- How does the flow of protons through the c-ring generate rotational torque? Mention the role of the aspartate (or glutamate) residue in the c-subunit.
- Calculate the theoretical P/O ratio for NADH. Why is the actual observed ratio in vivo often lower than the theoretical maximum?
- Describe the role of the Adenine Nucleotide Translocase (ANT) and the Phosphate Translocase in maintaining a steady supply of substrates for ATP synthesis.
- How does the Glycerol-3-Phosphate shuttle differ from the Malate-Aspartate shuttle in terms of the number of ATP molecules produced per cytosolic NADH?
- Explain the phenomenon of Respiratory Control. How does the concentration of ADP in the matrix regulate the rate of oxygen consumption?
- Write notes on: Q cycle, ATP synthase, uncouplers, Hydrogen ion concentration.
- Name the inhibitors acts on Complex I,II,III & IV
- Describe the flow of electrons from NADH++H+ produced in TCA Cycle to ATP synthesis.
- Give a brief account of the structure of ATP synthase. Discuss the mechanism of ATP synthesis.
