During a respirometer experiment, a sample of germinating seeds was observed to consume 150 mL of O₂ and release 135 mL of CO₂ . Identify the respiratory quotient (RQ) of the seeds and the biomolecule that is predominantly being used as the respiratory substrate.

Step-by-step solution

The respiratory quotient (RQ) is defined as the ratio of the volume of CO₂ evolved to the volume of O₂ consumed during respiration. RQ = Volume of CO₂ evolved Volume of O₂ consumed Substituting the given values: RQ = 135 mL 150 mL = 0.9 An RQ value of approximately 0.9 indicates that proteins are predominantly being used as the respiratory substrate, whereas fats typically have an RQ of around 0.7 and carbohydrates have an RQ of 1.0 . Answer: 0.9 and Proteins