Question

cell membrane and transport: learn how transporters keep cells healthy
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question 3 of 12
a key characteristic of active transport across a cell membrane is that:
moves substances against their concentration or electrochemical gradient requiring energy.
always involves the movement of water molecules across a membrane without energy input.
occurs spontaneously for all types of molecules without the need for membrane proteins.

Explanation:

Active transport across a cell - membrane moves substances against their concentration or electrochemical gradient, which requires energy input. Osmosis is the movement of water molecules and is passive (no energy input). Movement of all molecules continuously without membrane proteins is not a characteristic of active - transport.

Answer:

Moves substances against their concentration or electrochemical gradient requiring energy.