Explain6 marksChallenge
Germinating sunflower seeds store primarily lipids, while germinating wheat seeds store primarily starch. A student uses a simple respirometer to measure the respiratory quotient (RQ) of each type of seed during the first 48 hours of germination. The RQ of sunflower seeds is approximately 0.7, and the RQ of wheat seeds is approximately 1.0. The student calculates that, per gram of seed consumed, the sunflower seeds produce more ATP than the wheat seeds.
Explain these observations, with reference to:
- the relative energy values of lipids and carbohydrates
- the need for energy in germinating seeds
- the mechanisms of ATP synthesis