Lesson 10 - Yeast Unit Final SAQ
You have now completed the Yeast Unit. Here you will now have the opportunity to test your knowledge with a last set of self-assessment questions.
Self-Assessment Questions
1. ***Answer both parts of this question
a) Yeast cultures used in brewing are a collection of clones. What does this mean?
b) Using a suitable diagram, outline the stages of the cell cycle and describe how these clones arise when yeast grows.
2. **With the help of a diagram, describe the essential features of a vessel suitable for the storage of pitching yeast slurry. Explain how you would analyse a sample of yeast taken from the vessel to determine the total and viable yeast concentration using a light microscope.
3. ***What effects do sugar and oxygen have on the growth and metabolism of Saccharomyces yeast? Illustrate your answer with diagrams showing how brewing yeast generates and conserves energy, as well as maintaining redox balance when growing on wort.
4. **What is the difference between the genotype and phenotype of a cell? Describe the underlying principles that explain how metabolism is controlled at the level of the genotype and phenotype.
5. **What are the methods used to recover a yeast strain from storage and prepare a culture suitable for delivering to the brewery to begin propagation? How would you ensure the culture is suitable for use?