Module 8: Cell Respiration and Photosynthesis (Option C for SL only) 8.1 Cell Respiration

Assessment statements State that oxidation involves the loss of electrons from an element, whereas reduction involves a gain of electrons; and that oxidation frequently involves gaining oxygen or losing hydrogen, whereas reduction frequently involves losing oxygen or gaining hydrogen. Outline the process of glycolysis, including phosphorylation, lysis, oxidation and ATP formation. Draw and label a diagram showing the structure of a mitochondrion as seen in electron micrographs. Explain aerobic respiration, including the link reaction, the Krebs cycle, the role of NADH + H+, the electron transport chain and the role of oxygen. Explain oxidative phosphorylation in terms of chemiosmosis. Explain the relationship between the structure of the mitochondrion and its function.

8.1.1 State that oxidation involves the loss of electrons from an element, whereas reduction involves a gain of electrons; and that oxidation frequently involves gaining oxygen or losing hydrogen, whereas reduction frequently involves losing oxygen or gaining hydrogen. WordMeaning OxidationElectrons lost Oxygen gained Hydrogen lost (H + also called proton) ReductionElectrons gained Oxygen lost Hydrogen gained (H + ) PhosphorylationThe addition of a phosphate group DecarboxylationThe removal of a carbon

8.1.2 Outline the process of glycolysis, including phosphorylation, lysis, oxidation and ATP formation. (G3P) (fructose-1,6- bisphosphate) Reduction Substrate level phosphorylation – phosphate added directly onto ADP

8.1.3 Draw and label a diagram showing the structure of a mitochondrion as seen in electron micrographs. Label: Cristae, inner membrane, outer member, intermembrane space, matrix, ribosomes

8.1.4 Explain aerobic respiration, including the link reaction, the Krebs cycle, the role of NADH + H+, the electron transport chain and the role of oxygen. Pyruvate enters mitochondrion Enzymes in matrix remove a carbon (decarboxylation) and hydrogen (oxidation) Hydrogen is accepted by NAD + (forms NADH) The whole process is called oxidative decarboxylation The product is an acetyl group that reacts with coenzymeA (CoA) Acetyl CoA then enters the Krebs Cycle

8.1.4 Explain aerobic respiration, including the link reaction, the Krebs cycle, the role of NADH + H+, the electron transport chain and the role of oxygen.

Occurs in matrix of mitochondrion Decarboxylation occurs Oxidation/removal of hydrogen by NAD and FAD Substrate level phosphorylation

8.1.4 Explain aerobic respiration, including the link reaction, the Krebs cycle, the role of NADH + H+, the electron transport chain and the role of oxygen.

8.1.4 Explain aerobic respiration, including the link reaction, the Krebs cycle, the role of NADH + H+, the electron transport chain and the role of oxygen. Transfer of hydrogen to inner membrane carriers Hydrogen is pumped across inner membrane Creates a concentration gradient Electrons transferred between carriers Chemiosmosis Hydrogen ions passes down concentration gradient through ATP synthase Oxygen is the final electron acceptor and this forms water

8.1.5 Explain oxidative phosphorylation in terms of chemiosmosis. This involves the movement of protons (H + ) to provide energy for the phosphorylation of ADP to form ATP using the electron transport chain (ETC) ATP synthase found on the inner mitochondrial membrane uses the H + gradient to make ATP H + move passively down the concentration gradient back into the matrix 1 NADH = 3 ATP 1 FADH 2 = 2 ATP

8.1.6 Explain the relationship between the structure of the mitochondrion and its function. Cristae increase SA for ETC function Membranes provides barrier for proton accumulation Enzymes embedded in membranes in order for ETC and chemiosmosis to occur.

LocationReactantsProductsOxygen required? Glycolysis Link Reaction Krebs Cycle ETC + Chemiosmosis Summary Chart (1 glucose) Task: Try filling the chart out!

LocationReactantsProductsOxygen required? GlycolysisCytoplasm1 glucose 2 ATP 2 pyruvate 2 ATP 2 NADH No Link ReactionMitochondrial matrix 2 pyruvate2 acetyl CoA 2 NADH No (but will occur in the presence of O2) Krebs CycleMitochondrial matrix 2 acetyl CoA2 ATP 6 NADH 2 FADH 2 4 CO 2 (released) No ETC + Chemiosmosis Inner mitochondrial membrane + intermembrane space 6 NADH 2 FADH 2 3 x 6NADH = 18 2 x 2FADH2 =4 22 ATP Yes Summary Chart (1 glucose)

ATP usedATP madeNADH, FADH 2 made Total ATP Glycolysis 24 2 NADH x 3 = 6 (but 2 ATP are used to transport pyruvate into mitochondria) 8 Link Reaction 00 2 NADH x 3 = 66 Krebs Cycle ETC and chemiosmosis 00 6 NADH x 3 = 18 2 FADH 2 x 2= 4 22 Total 38 ATP Count