movement in and out of cells - key terms

Question 1

Define diffusion

Answer 1

Net movement of particles down the concentration gradient (high → low) as a result of their random movement.

Question 2

Define osmosis

Answer 2

Net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution) through a partially permeable membrane.

Question 3

Define active transport

Answer 3

Movement of particles through a cell membrane from a lower concentration region to a higher concentration region (i.e., against a concentration gradient), using energy from respiration.