Overview of respiration and glycolysisEdexcel International A Level Biology: Mind map

Exam questions on Overview of respiration and glycolysis

1. Glycolysis is the first stage of respiration in a liver cell supplied with glucose. In the later reactions of glycolysis a total of four molecules of ATP are made from each molecule of glucose.
   Explain why the net gain of ATP from glycolysis is two molecules per molecule of glucose.2 marks
2. A student investigates respiration in yeast. She adds yeast suspension to glucose solution containing methylene blue, a redox indicator that is blue when oxidised and colourless when reduced. Each tube is covered with a thin layer of oil and kept in a water bath, and she records the time taken for the blue colour to disappear. One tube is kept at 15 °C and another at 35 °C.
   Explain why the methylene blue becomes colourless more quickly at 35 °C than at 15 °C.2 marks
3. During a 100 m sprint, the muscle fibres in an athlete's leg respire anaerobically. In one fibre, 0.50 mmol of glucose is respired anaerobically by glycolysis alone.
   Calculate the amount of lactate and the net amount of ATP produced from the glucose in this fibre.3 marks