Practical: Investigating Respiration Flashcards
All 5 cards in this deck
In a respirometer, what is the purpose of the soda lime?
To absorb the carbon dioxide produced, so any decrease in gas volume is due only to the oxygen used.
What control should be used in a respirometer investigation into the rate of respiration of small organisms?
The same apparatus set up with no living organisms (e.g. glass beads) in place of the organisms.
True or false? A respirometer should be kept in a water bath at a constant temperature.
True. Temperature affects the rate of respiration, so it must be controlled (it also stops gas expanding as the apparatus warms).
What are the steps to calculate the rate of respiration from respirometer results?
e.g. the coloured drop moves 2.5 cm in 10 minutes
- Read the distance moved and convert the units: cm mm
- Divide by the time taken:
- Rate mm per minute
What happens to an organism's oxygen consumption as its body temperature rises?
It increases, because enzyme-controlled metabolic reactions speed up so more respiration occurs.