8.2 Cell respiration

IB Syllabus Statements

Understandings:

Cell respiration involves the oxidation and reduction of electron carriers.
Phosphorylation of molecules makes them less stable.
In glycolysis, glucose is converted to pyruvate in the cytoplasm.
Glycolysis gives a small net gain of ATP without the use of oxygen.
In aerobic cell respiration pyruvate is decarboxylated and oxidized, and converted into acetyl compound and attached to coenzyme A to form acetyl coenzyme A in the link reaction.
In the Krebs cycle, the oxidation of acetyl groups is coupled to the reduction of hydrogen carriers, liberating carbon dioxide.
Energy released by oxidation reactions is carried to the cristae of the mitochondria by reduced NAD and FAD.
Transfer of electrons between carriers in the electron transport chain in the membrane of the cristae is coupled to proton pumping.
Oxygen is the final electron acceptor.
In chemiosmosis protons diffuse through ATP synthase to generate ATP.
Oxygen is needed to bind with the free protons to maintain the hydrogen gradient, resulting in the formation of water.
The structure of the mitochondrion is adapted to the function it performs.

Applications and skills:

Application: Electron tomography used to produce images of active mitochondria.
Skill: Analysis of diagrams of the pathways of aerobic respiration to deduce where decarboxylation and oxidation reactions occur.
Skill: Annotation of a diagram of a mitochondrion to indicate the adaptations to its function.

Explain how the chemiosmotic theory led to a paradigm shift in the field of bioenergetics.
What is oxidase and reduced during cell respiration?
Explain how phosphorylation of molecules makes them less stable.
Outline what happens during glycolysis.
Outline the conversion of pyruvate into acetyl compound in aerobic respiration, to ultimately form acetyl coenzyme A in the link reaction.
Explain the coupling of oxidation of acetyl groups to reduction of hydrogen carriers to produce carbon dioxide in the Krebs cycle.
How is energy released by oxidation reactions carried to the cristae of the mitochondria?
Outline how the transfer of electrons between carriers in the electron transport chain on the cristae is coupled to proton pumping.
Explain how chemiosmosis generates ATP.
Explain how water is formed from cell respiration, and why oxygen is needed to bind with free protons.
How is the structure of the mitochondrion adapted to the function it performs?
Explain how electron tomography is used to produce images of active mitochondria.
Explain how you would analyze diagrams of the pathways of aerobic respiration to deduce where decarboxylation and oxidation reactions occur.
Explain how you would annotate a diagram of a mitochondrion to indicate the structural adaptations to their functions.