Biology / Unit 2 Bio 0364 short lesson, about 20 seconds
Primary and Secondary Active Transport
Captions available
The idea
Primary active transport uses ATP directly against a gradient; secondary active transport spends no ATP, drawing on a gradient a primary pump built.
In practice
Sodium's gradient, built by the sodium-potassium pump's ATP use, powers glucose's secondary transport at no added cost.
Where people slip
Secondary transport still moves a substance against its gradient — it borrows energy another pump paid for.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
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