The effect of temperature on cellular respiration in small organisms: practical

Key learning points

• Effect of temperature on aerobic cellular respiration investigated in small living organisms (e.g. germinating peas).
• The oxygen used by the respiring organisms in a set time can be measured using a simple respirometer.
• Identifying independent and dependent variables, and variables to control to increase the validity of the results.
• The height of coloured liquid in the capillary tube of the respirometer is measured at the start & end of the set time.
• Collecting repeat measurements at each temperature, and collecting data at different temperatures.

Keywords

aerobic

A process that requires oxygen.

cellular respiration

An exothermic chemical process that transfers energy for life processes, using glucose as fuel.

respirometer

Apparatus used to measure the rate of respiration in small organisms.

independent variable

The factor that we change in an experiment.

dependent variable

The factor that we measure in an experiment.

Common mistakes

• That small organisms and plants don't respire (only humans and other large animals).

  This lesson demonstrates experimentally that small organisms respire.