RP09 - Respiration in single celled organisms

Question 1

What is the function of methylene blue in this practical?

Answer 1

• Redox dye
• Turns blue to colourless indicating the end point

Question 2

Outline the procedure to investigate temperature on respiration of yeast?

Question 3

If yeast aerobically respires what way will the coloured liquid move and why?

Answer 3

1. Moves to the left
2. Yeast takes in O2
3. So volume of gas and pressure in container decreases
4. So fluid tube moves down pressure gradient towards organism

Question 4

In order to measure anaerobic respiration by measuring CO2 release how would you adjust the set up

Answer 4

• Remove the chemical that absorbs O2
• Make conditions anaerobic by..
• Adding a layer of oil to stop the diffusion of O2 in
• Add a chemical that absorbs O2
• Leave for an hour to allow O2 to be used up

Question 5

If yeast anerobically respires what way will the coloured liquid move and why?

Answer 5

1. Releases CO2
2. So volume of gas and pressure increases
3. Moves to the right