continue to breathe faster for several minutes after exercise to help our bodies break down the lactic acid produced. The amount of time it takes for a person’s breathing to return to normal after exercise is an indication of fitness level. The quicker your breathing returns to normal the fitter you are!
Anaerobic respiration in micro-organisms
Some bacteria and fungi, such as yeast, can carry out anaerobic respiration. Glucose is incompletely broken down in the absence of oxygen, producing alcohol and carbon dioxide. This is called fermentation.
Fig. 14 Anaerobic respiration takes place in muscles when there is not enough oxygen available.
Word equation for anaerobic respiration in micro-organisms: Glucose
Alcohol + Carbon dioxide + Small amount of energy
Research this Warming up before exercise and cooling down afterwards is a very important part of a good exercise routine. Research the importance of warming up and cooling down. Relate your findings to what you have learned about aerobic and anaerobic respiration in muscle cells.
Factors affecting the rate of respiration Temperature Amount of oxygen available Amount of glucose available Amount of water available
l l l l
Activity The effect of the availability of glucose on the rate of respiration in yeast
Yeast cells can carry out aerobic or anaerobic respiration. In this experiment the yeast will carry out aerobic respiration and the carbon dioxide produced will form foam. You can estimate the rate of respiration by looking at the amount of foam (CO2
) produced. This experiment investigates how the availability of glucose affects the rate of respiration.
Apparatus Three large graduated cylinders 1 g yeast for each cylinder 5 g each of glucose and artificial sweetener (like Splenda).
