A student observes that small nonpolar O2 molecules accumulate inside a cell whenever the extracellular O2 concentration is higher than inside, even when the cell's metabolism is blocked by a poison that depletes ATP. The teacher asks the student to identify the kind of transport responsible.
The transport process shown is BEST classified as:
- Acheck_circle
Simple diffusion (passive transport down a gradient)
- B
Active transport against a gradient
- C
Exocytosis
- D
Endocytosis
Explanation
Solutes move from high to low concentration without ATP - the defining feature of simple diffusion (passive transport).