Fermentaion Lab

Biology Lab:
Fermentation
1. Introduction

Fermentation is the conversion of carbohydrates such as sugar into an acid or an alcohol. Fermentation can refer to the use of yeast to change sugarinto alcohol or the use of bacteria to create lactic acid in certain foods. Fermentation occurs naturally in many different foods given the right conditions, and humans have intentionally made use of itfor many thousands of years.

Fermentation occurs under anaerobic conditions. As a consequence, sugars are metabolized predominantly to volatile fatty acids (VFAs). Additional major productsinclude lactic acid, carbon dioxide and methane. Proteins are also important substrates for fermentation.

Breakdown of sugars by bacteria and yeasts using a method of respiration without oxygen(anaerobic). The enzymes in yeast break down glucose to give two products: ethanol (alcohol) and carbon dioxide. Fermentation processes have long been utilized in baking bread, making beer and wine, andproducing cheese, yogurt, soy sauce, and many other foodstuffs.
In bread baking, the bubbles of carbon dioxide trapped in the dough make the bread rise. In the brewing process, complex sugars, such assucrose, are first broken down by yeast into simple sugars, such as glucose. Glucose is then further decomposed into ethanol and carbon dioxide. The ethanol produced is the alcohol in alcoholic drinks,such as beer and wine; the carbon dioxide puts bubbles into beers and champagne.
The word equation for fermentation is: glucose → ethanol + carbon dioxide. The symbol equation is:
C6H12O6 → 2C2H5OH +2CO2

2. Objective

To detect CO2 producing during anaerobic fermentation.

3. Research question

Do CO2 production in yeast depends on the presence of sucrose?

4. Variables

• Controlvariable: Temperature.
• Independent variable: CO2.
• Dependant variable: Sacarose solution.

5. Materials and method

Materials:

• Yeast solution
• Sacarose solution (sucrose)
• Two 200ml...