Unit 3 - Movement into and out of cells Flashcards
Difference in concentration
Concentration gradient
Diffusion
The net movement of particles from an area of high concentration an an area of low concentration, down a concentration gradient due to random movement
Type of cell membrane needed for diffusion
A permeable cell membrane
When concentration of areas is equal
Equilibrium
Type of energy needed for diffusion
Kinetic energy
Factors that can increase rate of diffusion
- Temperature increase
- Distance decrease
- Surface area increase
- Concentration gradient increase
- Mass of molecule decrease
Osmosis
The diffusion of water molecules across a partially permeable membrane
Solvent
Substance that is able to dissolve other substances to form a solution
Solute
The substance in a solution that is dissolved by the solvent
Dilute solution
Little dissolves solute compared to solvent
Concentrated solution
Lots of dissolved solute in comparison to solvent
Water potential
Measure of how freely water molecules can move
When concentration of a solution increases
Water potential decreases
Hypotonic solution
More solvent than solute - causes cells to swell or become turgid
Isotonic solution
Equal amounts of solute and solvent - causes a cell to be flaccid
Hypertonic solution
More solute than solvent - Causes a cell to plasmolyze - cytoplasm shrinks, cell membrane pulls away from cell well
Active transport
The movement of particles through a cell membrane from a region of lower concentration to a region of higher concentration using energy released from respiration
How active transport works
Carrier proteins in the cell membrane can change shape to pick up substances the cell needs using energy from respiration
Example of active transport
Nitrate ions moving into a root hair cell
