Which of the following best describes how a respirometer is used to measure fermentation in yeast cells?

• A. It measures the volume of carbon dioxide (CO_2) produced during fermentation.
• B. It measures the amount of oxygen (O_2) consumed during fermentation.
• C. It records the temperature change caused by metabolic reactions.
• D. It detects changes in glucose concentration in the fermentation medium.

Answer: (A)

Verified step by step guidance

1. Understand the concept of fermentation: Fermentation is an anaerobic process where yeast cells convert glucose into ethanol and carbon dioxide (CO₂) in the absence of oxygen (O₂). This process is commonly used in baking and brewing industries.
2. Identify the role of a respirometer: A respirometer is a device used to measure gas exchange during metabolic processes. In the context of fermentation, it is typically used to measure the production of CO₂, as this is a key byproduct of yeast fermentation.
3. Analyze the options provided: The correct description of how a respirometer measures fermentation in yeast cells should align with the production of CO₂, since oxygen consumption is not relevant in anaerobic fermentation, temperature changes are not directly measured by a respirometer, and glucose concentration is not the primary focus of this device.
4. Relate the measurement of CO₂ to fermentation activity: The volume of CO₂ produced is directly proportional to the rate of fermentation. By measuring CO₂, the respirometer provides insights into the metabolic activity of yeast cells during fermentation.
5. Conclude the correct answer: Based on the function of a respirometer and the nature of fermentation, the best description is that it measures the volume of CO₂ produced during fermentation.