Question

Yeast can also respire aerobically. The student repeated the investigation with a fresh sample of yeast in glucose solution, but without the oil. All other conditions remained the same. Explain what would happen to the volume of gas in the syringe if the yeast were only respiring aerobically

Answer 1

In aerobic respiration, yeast converts glucose into ATP, carbon dioxide, and water, leading to an increase in the volume of gas (mostly CO₂) in the syringe.

Step-by-step explanation:

If yeast were only respiring aerobically in a glucose solution without oil, the volume of gas in the syringe would likely increase due to the production of carbon dioxide (CO₂). During aerobic respiration, yeast converts glucose into ATP, carbon dioxide, and water.

This process is much more efficient than fermentation and can yield 36-38 ATP molecules per glucose molecule. The presence of oil in prior experiments might have limited the amount of oxygen available for the yeast, forcing it to undergo anaerobic respiration or fermentation, which would produce ethanol and CO₂.

Aerobic respiration does not produce ethanol, but does produce a significant amount of CO₂, which would be the gas filling the syringe in this case.