Anaerobic Respiration

1. Anaerobic Respiration Breaking down glucose in the absence of oxygen

2. Anaerobic Respiration in animal cells • The breakdown of glucose in cells in the absence of oxygen • During vigorous exercise when not enough oxygen to meet demands. • Glucose is only partly broken down and only 2 ATP molecules are made

3. Starts with glycolysis Glucose 2ADP + 2Pi 2ATP Pyruvic Acid Anaerobic respiration in animal cells Lactic Acid reversible

4. Effect of Lactic Acid • Formed when not enough oxygen present for aerobic respiration • Makes muscles sore – muscle fatigue • When exercise stops breathing takes in oxygen and the lactic acid is converted back to pyruvic acid • This is called the oxygen debt – the volume of oxygen required to convert lactic acid back to pyruvic acid

5. Anaerobic Respiration in plant and yeast cells • Again glucose partially broken down in absence of oxygen • Can occur when root cells growing in muddy soil or when yeast is used in brewing and bread making • Again only 2 ATP molecules are made

6. Glycolysis takes place first Glucose 2ADP + 2Pi 2ATP Pyruvic Acid Anaerobic Respiration in plant and yeast cells Ethanol and Carbon Dioxide NOT REVERSIBLE

7. Experiment • Demonstrating anaerobic respiration in yeast • Lime water to test for presence of carbon dioxide • Glucose boiled to remove oxygen • Layer of oil to prevent oxygen getting in

8. Experiment Results • Increase in temperature noted as yeast cells respire and release energy • Lime water turns cloudy showing the presence of carbon dioxide • Alcohol smell given off