Cell respiration

Topic 8.2

Essential idea: Energy is converted to a usable form.


8.2.1.U1 Cell respiration involves the oxidation and reduction of electron carriers

Place your mouse on the diagram to view electron carriers in Glycolysis

Oxidation reduction example for glycolysis

Place your mouse on the diagram to view electron carriers in the Electron Transport Chain

Oxidation reduction example for Krebs cycke

8.2.U2 Phosphorylation of molecules makes them less stable

How phosphorylation makes molecules unstable

8.2.U3 In glycolysis, glucose is converted to pyruvate in the cytoplasm

Summary of glycolysis

8.2.U4 Glycolysis gives a small net gain of ATP without use of oxygen

ATP production during glycolysis

8.2.U5 In aerobic cell respiration pyruvate is dearboxylated it and oxidized, and converted into a single compound and attached to                      coenzyme A to form a acetyl coenzyme A in the link reaction

Summary of the Link reaction

8.2.U6 In the Krebs cycle, the oxidation of acetyl groups is coupled to the reduction of hydrogen carriers, liberating                      carbon dioxide

Krebs cycle summary diagram

8.2.U7 Energy release by oxidation reactions is carried to the cristae of the mitochondria by NAD and FAD

NAD and FAD as electron carriers

8.2.U8 Transfer of electrons between carriers and the electron transport chain in the membrane of the cristae is coupled                      to proton pumping

Description of secondary protein structure

8.2.U9 In chemiosmosis proteins diffuse through ATP synthase to generate ATP

ATP synthesis via chemiosmosis

8.2.U10 Oxygen is needed to bind with free protons to maintain the hydrogen gradient, resulting in the formation of water

Oxygen as final electron acceptor

8.2.U11 The structure of the mitochondrion is adapted to the function it performs

Mitochondrion: Structure vs Function

Shown below are the different structures found in the mitochondrion. Each structure has a specific function which allows for the efficient production of ATP during aerobic respiration in the cell.

Mitochondrial outer membrane> Outer Membrane Allows for compartmentalisation of aerobic respiration and keeps contents separate from rest of the cell.
Mitochondrial inner membrane Inner membrane Location of the electron carriers of the electron transport chain and ATP synthase.
Mitochondrial inner membrane space Inner Membrane Space The small space between inner and outer membranes for accumulation of a high concentration of protons formed by chemiosmosis. The high concentration of protons are used in the production of ATP.
Mitochondrial matrix Matrix The fluid containing enzymes of the Krebs cycle and the Link Reaction.
Mitochondrial cristae Cristae Forms a large surface for the electron transport chain and oxidative phosphorylation.


8.2.A1 Eelectron tomography used to produce images of active mitochondria

Electron tomography link Electron tomography mitochondrion
Use of electron tomography


8.2.S1 Analysis of diagrams of the pathways of aerobic respiration to deduce decarboxylase and oxidation reactions occur

Place your mouse on the figure to view where decarboxylation occurs

Decarboxylation aerobic respiration

Place your mouse on the figure to view where oxidation reactions occurs

Oxidation reactions aerobic respiration

8.2.S2 Annotation of a diagram of a mitochondrion to indicate the adaptations to its functions

Label and annotate the diagram of the mitochondrion below.

Placing your mouse on the diagram to view the labels and annotations.

Mitochondrion diagram to be annotated
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