Answer:
Here is a procedure that demonstrates the role of yeast in fermentation using the materials listed:
Materials:
- Distilled water
- Bakers yeast
- Dextrose/glucose/sucrose (one of these sugars)
- Plastic water bottle
- Beaker
- Hot plate
- Graduated cylinder
- Balloons
- Funnel
Procedure:
1. Start by measuring out 100 mL of distilled water using the graduated cylinder and pouring it into the plastic water bottle.
2. Add 1 gram of baker's yeast to the water in the bottle and stir gently to mix.
3. Next, add 5 grams of dextrose, glucose, or sucrose to the bottle using the funnel.
4. Gently swirl the bottle to mix the yeast and sugar with the water.
5. Place the balloon over the mouth of the bottle, making sure it is securely attached.
6. Set the bottle aside in a warm, dark place for at least 30 minutes to allow fermentation to occur.
7. While waiting for the fermentation to occur, fill the beaker with water and place it on the hot plate to heat.
8. Once the water in the beaker has reached a boil, turn off the hot plate.
9. Carefully remove the balloon from the mouth of the bottle and use the graduated cylinder to measure the volume of gas that has been produced in the bottle. Record this value.
10. Carefully pour the hot water from the beaker into the plastic water bottle and swirl to mix.
11. Quickly replace the balloon over the mouth of the bottle.
12. Observe the balloon and record any changes in size or shape that occur over the next few minutes.
13. Dispose of the contents of the bottle in a proper manner.
Step-by-step explanation:
In this procedure, the role of yeast in fermentation is demonstrated by combining yeast, sugar, and water in a bottle and observing the production of gas (carbon dioxide) as a result of the fermentation process. The balloon placed over the mouth of the bottle allows the gas to collect and be measured. Heating the bottle after the fermentation process speeds up the chemical reaction and causes an increase in gas production, which is observed by the expansion of the balloon.