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Award 1 mark for each of the following structures clearly drawn and labelled correctly. TR e Chie B R . outer membrane intermembrane space / outer compartment inner membrane matrix cristae ribosome naked / circular DNA ATP synthase Do not accept plasma membrane. 5. Explain how the structure of the mitochondrion allows it to carry out its function efficiently. 8 marks HL membranes to compartmentalise / separate from processes in the cytoplasm small size gives large surface are to volume ratio large surface area to volume ratio allows rapid uptake / release of materials matrix contains enzymes of the Krebs cycle / matrix carries out Krebs cycle inner membrane invaginated / Infolded / forms cristae to increase the surface area large surface area glves more space for electron transport chain / oxidative phosphorylation inner membrane contains ATP synthetase / ATPase / stalked particles that make ATP (narrow) gap between Inner and outer membranes / intermembrane space ( must be stated or labeled) pH / H+ / proton concentration gradient rapidly established / steeper chemiosmosis therefore more efficient / chemiosmosis can occur inner membrane contains the electron transport pathway DNA present to act as genetic material ribosomes for protein synthesis some proteins do not need to be imported 6. Outline the process of glycylosis. 5 marks HL glucose/hexose/6C sugar converted to form pyruvate splitting of hexose (phosphate) / lysis oxidation of triose phosphate net gain of 2 NADH (+ H+) / reduced NAD net gain of 2 ATP substrate level phosphorylation occurs In cytoplasm of cell no 02 required under feedback control / inhibition 7. Explain the reactions that occur in the matrix of the mitochondrion that are part of aerobic respiration. § marks HL pyruvate is decarboxylated/ CO2 removed link reaction/ pyruvate combined with CoA/ ethanoyl/acetyl CoA formed pyruvate Is oxidized/ hydrogen removed reduction of NAD/ formation of NADH + H+ whole coversion called oxidative decarboxylation Krebs cycle C2+C4-—-—->0C6 C6 ---> CS5 giving off CO2 C5 ---> C4 giving off CO2 hydrogen atoms removed collected by hedrogen-carrying coenzymes ATP formed by substrate level phosphorylation oxygen accepts electrons/ oxygen combines with hydrogen total yield perturn of Krebs cycle = 2 C02,, 3 NADH + H+, 1 FADH2, 1 ATP (directly produced) 8. Explain the process of aerobic respiration. 8§ marks HL by glycolysis, glucose is broken down into pyruvate (two molecules) in the cytoplasm with a small yield of ATP/ net yield of 2 ATP and NADH + H+/ NADH