How Does Sucrose Affect Yeast

CONTENTS PAGE:

1.0 Abstract

2.0 Introduction

2.1 Aim

2.2 Background information

2.3 Hypothesis

3.0 Materials

4.0 Procedure

5.0 Results

6.0 Discussion

7.0 Conclusion

8.0 Bibliography

9.0 Appendixes

1.0 Abstract –

To investigate the effect of the yeast and the water when it was at different temperatures such as; ice bath, room temperature, 40° water bath and 80° water bath. The experiment took place when a balloon was placed on top of the test tube and the balloon expanded. The largest part of the balloon was then measured to see how much the balloons circumference had increased by.

2.0 Introduction

2.1 Aim –

The aim of this experiment is to investigate the effect of yeast growth temperatures.

2.2

The enzyme to break that double sugar into single sugars is fairly commonplace among living organisms (and certainly in yeast). Plus, under slightly acidic conditions, sucrose will break into the two single sugars automatically. Thus, sucrose breaks down to glucose plus fructose. Yeast, a microscopic, one-celled organism belonging to the group of organisms called fungi. There are many kinds of yeasts, some of them of great importance to humans. Yeast is necessary to make leavened bread, beer, cheese, wine, and whiskey. It is rich in B vitamins; a form of yeast called brewer's yeast is used as a diet supplement. Yeast is also used in genetic engineering to produce large quantities of certain hormones and enzymes, which are used for such medical purposes as healing wounds and reducing inflammation. Some types of yeast, however, cause disease; candidiasis, a skin infection, is an example.Yeasts are found in the soil, in water, on the surface of plants, and on the skin of humans and other animals. Like other fungi, yeasts obtain food from the organic matter around them; they secrete enzymes that break down the organic matter into nutrients they can absorb. Yeast microbes react different in varying environments. mixing yeast with sugar and cold water, would not have had the same results. The environment matters, and if the water were too hot, it would kill the yeast microorganisms. The yeast alone does not

Flasks were labelled A to D (refer to appendix 1)

2. 80 mL of tap water was added (neutral pH only) to each flask, where they were placed in beakers at following conditions: Flask A – in ice bath. Flask B – at room temperature. Flask C – in 40 C water bath. Flask D –in 80 C water bath. (refer to appendix 1) (refer to appendix 7)

3. 5 g of sucrose was dissolved in each flask. (refer to appendix 2and3)

4. 4 g of baker's yeast was added to each flask and stirred. (Refer to appendix 2and3)

5. a balloon was placed on each flask and sealed securely with a rubber band

6. The beaker was then placed into the correctly labelled beaker which held the water temperature which was monitored with thermometers. (refer to appendix 4)

7. As soon as the flask with the balloon was placed in the larger flask, the stop watched began timing until 15 minutes had passed. (refer to appendix 5)

8. After the 15 minutes are up, a string was placed around the balloon to see the growth/effect of the yeast in the certain water temperature. (refer to appendix 6)

5.0 Results –

Temperature Trial 1 (cm) Trial 2 (cm) Trial 3 (cm) Trial 4 (cm) Average (cm) Range (cm)

Room temperature 11 12.5 Failed 13 9.125