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12 Cards in this Set
- Front
- Back
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What are yeast? |
Single celled organisms that can be grown in culture |
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What respiration can they use? |
Aerobic and anaerobic |
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What do both of these types of respiration produce? |
CO2 |
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How can you measure CO2 production? |
Use a gas syringe to collect CO2 |
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What will this tell you? |
The rate of respiration |
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What can you do to measure the rate of aerobic respiration in yeast? |
Put a respiratory substrate with known volume and concentration in a test tube. Add a pH buffr and place in a water bat. Add a mass of dried yeast and stir. Attach a bung and gas syringe. Start a stop watch and measure volume every minute for 10 mins |
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What pH should the buffer be? |
4.6 |
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Why is the test tube placed in a water bath? |
To allow the solutions to equilibriate to the correct temperature |
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What volume of gas should be produced with no yeast present? |
None |
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How can you ensure your result is reliable? |
Do it at least three times and calculate a mean |
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How do you measure the rate of anaerobic respiration in yeast? |
Set up apparatus as above but after the yeast has dissolved, trickle some liquid paraffin in the test tube. Then record as normal |
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What does the liquid paraffin do? |
It settles on top to cover the surface, preventing oxygen from entering so the conditions are anaerobic |
