WJEC Biology for A2 Level: Revision Workbook

Q2 [AO1, AO2] Aerobic respiration occurs in a number of stages. a) Complete the table using a tick ( ✓ ) to indicate which statements apply to the following stages in respiration, or a cross ( ✗ ) if they do not. (4) Statement Glycolysis Link reaction Krebs cycle Electron transport chain Occurs in the mitochondrial matrix ATP produced by substrate- level phosphorylation FAD reduced NADH 2 oxidised b) Explain the role of ATP in glycolysis. (3) ......................................................................................................................................................................................................................................................................................................................................... ......................................................................................................................................................................................................................................................................................................................................... ......................................................................................................................................................................................................................................................................................................................................... ......................................................................................................................................................................................................................................................................................................................................... c) During strenuous exercise muscles may temporarily respire anaerobically. Explain why it is important for the muscles of an athlete to convert pyruvate into lactate (lactic acid). (3) ......................................................................................................................................................................................................................................................................................................................................... ......................................................................................................................................................................................................................................................................................................................................... ......................................................................................................................................................................................................................................................................................................................................... ......................................................................................................................................................................................................................................................................................................................................... EXAM T I P Don’t leave any boxes blank. If you are unsure have a guess, you have a 50:50 chance of getting it right! 3.1 Importance of ATP and 3.3 Respiration | 15 Unit 3 Energy, Homeostasis and the Environment Copyright: Sample material