Respiration

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Question 13
Medium

The respiratory quotient (RQ) of different respiratory substrates can be calculated using the formula:

RQ=Volume of carbon dioxide producedVolume of oxygen consumed\text{RQ} = \frac{\text{Volume of carbon dioxide produced}}{\text{Volume of oxygen consumed}}RQ=Volume of oxygen consumedVolume of carbon dioxide produced​

The table below gives the standard RQ values for three pure respiratory substrates:

SubstrateStandard RQ value
Glucose (Carbohydrate)1.0
Protein0.8
Lipid0.7

In an investigation into the respiration of a sample of tissue, the following measurements were recorded:

  • Volume of oxygen consumed = 150 cm3150\text{ cm}^3150 cm3
  • Volume of carbon dioxide produced = 112.5 cm3112.5\text{ cm}^3112.5 cm3

Calculate the RQ for this tissue sample and suggest which combinations of respiratory substrates were being used.

[4]

Respiration Questions

  1. GCSE
  2. /Biology
  3. /Respiration