volume_mute
Moving substances against a concentration gradient
publish date: 2026/06/16 20:56:38.205074 UTC
volume_mute
To move substances such as glucose across a cell membrane against a concentration gradient, which of the following is true?
Correct Answer
energy has to be expended
Explanation
Moving substances against a concentration gradient requires energy to be expended — this is called active transport. Moving molecules from low concentration to high concentration is thermodynamically unfavorable and requires ATP energy. This is in contrast to diffusion and osmosis, which are passive processes moving substances down their concentration gradients.
Reference
Biology: A Self-Teaching Guide