transport in cells

• diffusion is when particles move from a high concentration to a low concentration across a partially-permable membrane
• oxygen diffuses from the alveoli to the blood
• osmosis is the movement of water molecules from an area of high water concentration (weak dilute solution) to and area of low water concentration (strong dilute solution) through a partially-permable membrane
• isotonic solutions are 2 solutions with the same concentration of solute
• hypertonic solutions is when one of two solutions has a higher concentration of solute
• turgid is when a plant cell is fully inflated with water
• plasmolysed is when a plant cell has lost water causing the cell membrane to be pulled away from the inside of the cell wall
• flaccid is when a plant cell is limp due to the reduction of pressure from water
• the movement of carbon dioxide into a leaf is passive movement
• active transport is when molecules move across a cell membrne from a lower concentration to a higher concentration
• in active transport particles move against the concentration gradient
• active transport required energy (ATP)
• carrier proteins pick up specific molecules and take them through the cell membrane against the concentration gradient
• passive transport is the movement of substances across the membrane without any input of energy from the cell
• osmosis and diffusion are passive transport
• active transport is the movement of materials from a lower concentration to a higher concentration using energy
• you can use active transport to get passive transport to happen
• 1. use a cork borer to cut a piece of plant tissue 5cm in length 2. on a tile cut the skin off and cut the piece to 4cm 3. dry the plant tissue and weigh it recording the mass 4. put it in a test tube with 1m concentration of sugar solutions 5. leave it for 2 hours and then take them out, dry them and reweigh them 6. repeat for other concentrations
• dialysis machines remove the urea from the blood because they can pass through the partially permeable membrane and larger protein molecules can't and blood and water can but is on both sides so doesn't