diffusion and osmosis Flashcards
what is the cell membrane?
a double layered membrane responsible for controlling the movement of material in and out of the cell
most cells are surrounded by (essential substances) solutions that contain what 4 things?
water, oxygen, minerals, nutrients
to be alive, essential substances must ______ and ______ the cell, so the molecules ___________
enter / exit / move through the cell membrane
cell membranes are __________ to control the movement of materials in and out of the cell
selectively permeable
cell membranes act as a _________ to ______ the contents of the cell from its surroundings
barrier / separate
what is diffusion?
small dissolved substances move from higher concentration area to lower concentration area until they are equally distributed
what happens when equilibrium is reached?
substances diffuse across the cell membrane in both directions
what is osmosis?
water molecules move from high water concentration area to low water concentration area
water moves from low solute to high solute area
what is hypotonic?
water outside the cell is greater than water inside the cell
water moves into the cell
when water moves into an animal cell, what might happen?
the cell will burst (lysis)
when water moves into a plant cell, what might happen?
the cell will become turgid
what is isotonic?
water outside the cell is equal to water inside the cell
water moves in and out of the cell equally
what is hypertonic?
water outside the cell is smaller than water inside the cell
water moves out of the cell
when water moves out of an animal cell, what might happen?
the cell will shrink and appear wrinkled (crenation)
when water moves out of a plant cell, what might happen?
the cytoplasm will pull away from the cell wall (plasmolysis)
