alleryStart learning →What is a photoact?
AThe ejection of an electron from a reaction centre
BThe reflection of green light from a leaf surface
CThe splitting of a sugar into two smaller units
DThe opening of a stoma in response to light
Answer & Solution
Correct answer: A. The ejection of an electron from a reaction centre
1. The reaction centre contains a pair of chlorophyll a molecules with a special property.
2. Those two chlorophylls can undergo oxidation upon excitation and actually give up an electron.
3. That ejection of an electron from a reaction centre, using the energy of an absorbed photon, is a photoact.
4. It is the step at which light energy is finally converted into an excited electron.
_Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 8 "Photosynthesis", section 8.2 The Light-Dependent Reactions of Photosynthesis_
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