Describe an experiment to show that anaerobic respiration takes place in yeast.

Yeast break down glucose (food) into ethanol, carbon dioxide and releases energy. It is a type of cellular respiration that takes place in the absence of oxygen to produce energy

C₆H₁₂O₆ (fermentation) → 2CH₃CH₂OH + 2CO₂

Experiment

• Put equal amount of glucose solution into bottles A and B
• To bottle B add yeast but no yeast to bottle A
• Close each bottle with a tight balloon and wait for about an hour

Observation

Balloon of bottle B inflates with awhile that of bottle does not

Explanation

Yeast in bottle B ferments glucose to produce carbon dioxide that inflates the balloon. A tight balloon prevents entry of oxygen and thus fermentation occurs anaerobically.

Bottle A without yeast no fermentation occurs and no gas produced