A student measures the respiratory quotient (RQ) of a seed and obtains a value of 0.7. Which substrate is the seed most likely respiring?

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Question

A student measures the respiratory quotient (RQ) of a seed and obtains a value of 0.7. Which substrate is the seed most likely respiring?

Accepted Answer

Lipid only — An RQ of approximately 0.7 is characteristic of lipid respiration. Glucose (carbohydrate) respiration gives an RQ of 1.0. Protein respiration gives an RQ of approximately 0.9. Ethanol is not a typical primary respiratory substrate and is not tested in this context at IGCSE.

Answer

Glucose only

Answer

Ethanol only

Answer

Lipid only

Answer

Protein only

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