[Campbell Biology P.244] According to Figure 10.11 a and the accompanying text, what happens... | Practice Question

According to Figure 10.11 a and the accompanying text, what happens immediately when an isolated chlorophyll molecule absorbs a photon and its electron is boosted to an excited state?

  • A: The molecule undergoes immediate chemical reactions to produce ATP and NADPH.
  • B: The excited electron drops back to the ground state, releasing excess energy as both heat and fluorescence (light).
  • C: The chlorophyll molecule becomes permanently stable in the excited state.
  • D: The molecule immediately transfers its excited electron to another pigment molecule.

Explanation

When an isolated chlorophyll molecule absorbs a photon, its electron is boosted to a higher energy orbital excited state . This excited state is unstable, and the electron quickly drops back to its ground-state orbital, releasing the excess energy as both heat and a photon of light, known as fluorescence.