Biology / Unit 3 Bio 0604 short lesson, about 20 seconds
Photorespiration: RuBisCO's Oxygenase Activity
Captions available
The idea
RuBisCO sometimes binds oxygen instead of carbon dioxide, starting photorespiration, which spends ATP and releases fixed carbon without producing sugar.
In practice
On a hot day with stomata partly closed, oxygen outpaces carbon dioxide inside the leaf, so RuBisCO binds oxygen more often.
Where people slip
Photorespiration wastes energy and forfeits carbon already fixed, rather than merely reversing the Calvin cycle.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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