Students should be able to:
In this laboratory activity you will investigate the processes of fermentation and cellular respiration. Fermentation is anaerobic while cellular respiration is aerobic. The laboratory procedures for this exercise allow you to create the anaerobic and aerobic conditions. You will be collecting data and analyzing it via graphs and calculations, and drawing some basic conclusions about the respiratory processes carried out by yeast (anaerobic) and peas (aerobic).
Alcoholic fermentation as carried out by yeasts, is an anaerobic process. In this process, glucose (or other simple sugars) are incompletely degradated and the chemical energy released is captured and used to converted 2 ADP to 2 ATP / glucose molecule. The overall equation for this process is:
C6H12O6 + Yeast ---------------> 2 CO2 + 2 C2H5OH + 2 ATP
The above process is used in the manufacture of beer, wine, and bread.
Some organisms, such as lactic acid bacteria, carry out lactate fermentation that results in the production of lactate instead of the alcohol, ethanol. This process is used in the production of yogurt, cheese, and chocolate. The overall equation for this process is:
C6H12O6 + Lactic Acid Bacteria ------> 2 CO2 + C3H6O3 + 2 ATP
Cellular respiration, unlike fermentation, is an aerobic process. In cellular respiration glucose is completely degradated and the chemical energy released is captured and used to convert ADP to ATP, and ultimately results in the production of 36 to 38 ATP molecules / glucose molecule. The energy produced in this manner is much greater than that produced in fermentation. The overall equation for this process is:
C6H12O6 + 6O2 ------------> 6CO2 + 6 H2O + 36-38 ATP
Pre-Lab Activity #1 - Setups for Respiration Exercises
Print out the following pictures of the setups so you may refer to them in lab. Just Click on the Picture
Yeast Respiration: Pea Respiration:
Respirometer Respirometer Content
Pre-Lab Activity #2 - Acquisition of Materials
Download and print out the following:
The Laboratory Activities and Data Collection
Lab Activity #1 - Measuring Yeast Fermentation (Anaerobic) Using Respirometers
Fill each of the 4 small test tubes up to the 5 cm mark with the sugar solutions as directed in the following chart.
Lab Activity #2 - Measuring Pea Respiration (Aerobic) Using Respirometers
Post-lab Activity and Data Analysis
Results and Analysis:
Clean up your lab area and return all materials to their proper location.
Graph the data from the Yeast Fermentation Exercise. The graph parameters are:
Graph the Corrected Difference data from the Pea Respiration Exercise. The graph parameters are:
Answer the Post-Lab Questions