Topic 3 Movement into and out of cells

• Diffusion is the net movement of particles from a region of higher concentration to a region of lower concentration down a concentration gradient.
• Factors affecting rate of diffusion includes : temperature, difference of concentration, surface area and distance of which it diffuses.
• The greater the difference in the concentration of substance on either side of a memrane, the faster it will diffuse.
• Thicker wall will result in slower rate of diffusion.
• Osmosis is the net movement of water molecules from a region of higher water potential to a region of lower water potential down the water potential gradient through a partially permeable membrane.
• Hypotonic is when theres a higher water potential outside cell and lower water potential inside cell.
• Hypotonic solution makes the cell contents push against the cell wall and cell becomes turgid.
• Hypertonic is when theres lower water potential outside cell and higher water potential inside cell.
• Hypertonic makes cell shrink and cell membrane pull away from the cell wall and becomes flaccid. (plasmolysed)
• Animal cell swell and burst in hypotonic solution. (in water)
• Isotonic solution is when the concetration is equal outside and inside the cell.
• Animal cell will shrink and shrivel in hypertonic. (concentrated solution)
• Active transport is the movement of molecules or ions through a partially membrane from a region of lower concentration to a region of higher concentration against a concentration gradient using energy released from respiration.
• Root hair cell have a higher concetration of mineral ions than soil thus the ions move into root hair cells via active transport.