Fermentation Lab
Purpose:
To observe the process of fermentation in a living organism, yeast (Saccharomyces).
Materials:
125 ml Erlenmeyer Flask (3) Yeast (Saccharomyces) Hot Plate /Thermometer
7 inch Balloon (3) Scale Piece of String
Sugar Ruler Pencil/Pen/ or China Marker
Procedure:
1) Gather the needed materials. Label the 125ml Erlenmeyer flasks 1, 2, and 3. Put your group’s name on each to identify your own flasks.
2) Pre-stretch the balloons. Do this by stretching them and blowing them up and letting out the air.
3) Set up the following flasks using the procedure for each flask. Make sure to be accurate in your measurements.
Flask #1: 75 ml of warm water (40o C)
6.5 grams of sugar
Put the pre-stretched balloon immediately over the top of the flask
Flask #2: 75 ml of warm water (40o C)
1 gram of yeast
Put the pre-stretched balloon immediately over the top of the flask
Flask #3: 75 ml of warm water (40o C)
6.5 grams of sugar
1 gram of yeast
Put the pre-stretched balloon immediately over the top of the flask
4) Gently stir the flask to mix the materials in each flask. Allow the flasks to sit for 24 hours
Day 2
5) Use a piece of string to measure the circumference of each balloon. If the balloon does not look noticeably different from the start of the experiment, calculate the circumference of the balloon as zero.
Fill out the data table.
6) Use the circumference of the balloon and the following equations to calculate the diameter of the balloon. Fill out the data table C = 2pr d = 2r
7) Calculate the volume of gas produced using the following equation. Fill out the data table.
Volume of Gas Produced = 4.187 x (diameter of balloon in cm / 2)3
8) Clean up your lab supplies. Make sure to clean out all flasks thoroughly.
Data/Results:
Discussion:
1) What process was observed in this lab?
Alcoholic fermentation was observed in this lab.
2) What gas was produced in this process? What observation was seen to show this production?
The gas produced in this process is carbon dioxide. The creation of this gas was observed by the size of the balloon at the top of the flask.
3) What is the overall equation of cellular respiration? Circle the reactants, Place a box around the products.
(C6H12O6+6O2) → [6CO2+6H2O+ATP]
4) Which flask or flasks had no observable gas production? Why is this so?
The flask with the yeast and the sugar had the most production due to a large amount of glucose to be broken down.
5) Which flask produced the largest volume of gas? Why might this be so?
The flask that produced the most volume of gas is the flask with yeast and sugar. This is because of a large presence of sugar for the yeast to break down. Larger amounts of reactants produce larger amount of products.
6) What are some observable indicators that a chemical reaction was taking place inside some of the flasks? (Name two)
Bubbling and fizzing inside the flask.
7) How are photosynthesis and cellular respiration connected in a biochemical pathway?
The reactants of cellular respiration are the products of photosynthesis.
