Using a respirometer

• What does RQ stand for in the context of respiration?

  Respiratory Quotient
• How is the RQ value calculated?

  By dividing the amount of carbon dioxide produced by the amount of oxygen consumed
• What can the RQ value help determine about an organism?

  Which respiratory substrate is being utilized
• What is the role of a respirometer in measuring respiration?

  • Measures oxygen consumption
  • Measures carbon dioxide production
  • Calculates RQ value
• What happens to oxygen in a respirometer during aerobic respiration?

  Oxygen is consumed by the organism
• What does potassium hydroxide solution do in a respirometer?

  It absorbs carbon dioxide produced during respiration
• What does the movement of the colored liquid in a respirometer indicate?

  The volume of gas consumed or produced
• How can the respirometer be reset for repeated measurements?

  By using a three-way tap to push air back into the vessel
• Why is gauze used in respirometer experiments with living organisms?

  To prevent the organisms from touching harmful solutions
• What is a monometer in the context of respiration experiments?

  A device similar to a respirometer that measures gas exchange
• How does a monometer ensure accurate measurements during respiration experiments?

  By using glass beads as a control to maintain volume
• What is the significance of using glass beads in a monometer experiment?

  They help ensure that any movement of liquid is due to respiration
• What variables should be controlled in a respiration investigation with yeast?

  Temperature, volume, concentration, and mass of the organism
• Why is it important to control the temperature in yeast respiration experiments?

  Temperature affects the rate of respiration
• What is a pH buffer used for in respiration experiments?

  To maintain a stable pH for enzyme activity
• How would you calculate the rate of oxygen uptake if given the diameter of a capillary tube and the distance the liquid moved?

  Using the formula $\pi r^2 \times \text{length}$ and dividing by time
• What is the significance of significant figures in calculations for exams?

  To ensure precision and accuracy in reporting results
• If the diameter of a capillary tube is $0.1 \text{ mm}$ and the liquid moved $3 \text{ mm}$, how would you express the radius in the calculation?


  The radius would be $0.05 \text{ mm}$
• What is the final result of the oxygen uptake calculation expressed in standard form?

  $1.18 \times 10^3 \text{ mm}^2/\text{hour}$
• What are the key considerations when conducting a respiration investigation?

  • Control variables (temperature, volume, concentration, mass)
  • Use of appropriate equipment (respirometer or monometer)
  • Ethical treatment of organisms
  • Accurate measurement and calculation techniques
• What are the steps to calculate the volume of gas consumed in a respirometer?

  1. Measure the distance the liquid moved.
  2. Calculate the radius from the diameter.
  3. Use the formula $\pi r^2 \times \text{length}$.
  4. Divide by the time taken for the measurement.