| Fermentation and Food |
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Review Go back in your notebook and look up the information you have on fermentation and answer the following question: Under what condition(s) do organisms conduct fermentation? Next, click on the link on the right called “Fermentations of Importance to Humans” and answer the following questions: Brewing Beer 1. What is fermented to make beer? What must first happen to the starch in the grains before fermentation can take place? What kind of microorganism does the fermentation? “Malt” 2. When the grain is soaked in water and germinates (sprouts), which enzymes does it produce to help break down substances within the grain? What are the names of the substrates that these enzymes work upon? “Mash” 3. Using what you have learned about chemical reactions, why is the incubation temperature raised to 65-70 ºC? 4. At the end of the incubation period, why is the temperature raised even higher to 75 ºC? Think back to our mini-unit on enzymes, what is this “deactivation” called? “Boiling” 5. Why do you want to sterilize the liquid? “Fermentation” 6. What is the Genus and species name of the yeast that is going to do the actual fermentation? 7. What are the 2 waste products that the yeast produce when fermenting the glucose? 8. Alcohol is a poison to cells. What do you think happens to the yeast when the alcohol level begins to rise? How would this affect fermentation? “Aging” 9. What happens to the yeast during this process? Do you think they are alive or dead at this point? Bread 10. How is the fermentation of beer similar to the fermentation that occurs when bread is made? 11. What 3 things are providing food for yeast? 12. Compare the Genus and species of the yeast that is generally used to ferment beer (question #6) with the name of the yeast used to ferment bread. Any similarities? Any differences? 13. What causes the bread to rise? 14. What do you think the high temperature (over 100 ºC) of baking does to the yeast organisms? What do you think it does to the alcohol in the bread? Yogurt 15. What organism is used to ferment milk to make yogurt? How does this compare with the organism that ferments beer and bread? 16. What is the name of the sugar that is used as food for these microorganisms? 17. Once again think back to our mini-unit on enzymes, what is the name of the enzyme that these microorganisms produce to help break down this sugar? 18. Yogurt has a somewhat “sour” taste; this is due to an acid that the microorganisms produce as a by-product of fermentation. What is the acid’s name? 19. Why must you first kill the microorganisms that might be contaminating the milk before you can add the “starter culture”? 20. What are the names of the bacteria that are added to do the fermentation? Cheese 21. In general, how is cheese fermentation similar to yogurt making? (Name 2 similarities) 22. How does the time used to make cheese compare to the time needed to make yogurt? Other Products 23. Aside from dairy products and beverages, look at the chart of fermented foods and name all of those that you or your family eats. |
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