Misconception One: Sudents should be cautioned against
making statements that “energy is created” when it is converted from one form to another. This might be a good time to review the principle of the conservation of energy (the first law of thermodynamics).
How to overcome this misconception: The laws of thermodynamics should be reviewed as a diagnostic on the introduction day to the unit. This is because this concept will be applied throughout the unit.
Activity Ideas: Definition worksheet, mini jigsaw, hangman
Misconception Two: It is a common misconception that fermentation only occurs when cells are forced into an anaerobic situation and have to respire and produce energy through a pathway which requires little or no oxygen. This is not the case, as many yeasts, which are the most commonly used organism in fermentation processes, will respire using a fermentation pathway preferentially even in the presence of abundant oxygen.
How to overcome this misconception: Provide students with a list of organisms that will use the pathway of fermentation even in the presence of oxygen (also include obligate anaerobe example: Clostridium tenani)
Activity Ideas: Yeast Inquiry, Application of organisms that respire anaerobically, Three Fermentation Exercises
Misconception Three: Fermentation is misunderstood by many students. Students may not recognize that it functions to regenerate NAD+ and instead think that it yields additional ATP. You may be surprised to know that many students do not realize that yeast are living organisms. Many have the mistaken view that baking yeast are dead, or they think of yeast as a set of enzymes rather than living cells.
How to overcome this misconception: Give students a recap of their grade 11 Diversity of Living Things strand, where they talked about yeast when discussing the Kingdom Fungi.
Flow charts should be used to show students what different pathways can be used with or without oxygen.
Stress that during glycolysis the only way for the cycle to keep going is to regenerate NAD+.
Activity Ideas: Yeast Inquiry, flow charts, Application of organisms that respire anaerobically, Is Yeast Alive?, Three Fermentation Exercises