transport across membrane

• the membrane is made from proteins and phospholipids
• osmosis doesn't require energy its the movement of water molecules from an area of high water concentration to an area of low water concentration down a concentration gradient across a selectively permeable membrane
• diffusion is passive so doesn't require energy it is the movement of particles from an area of high concentration to an area of low concentration down a concentration gradient across a selectively permeable membrane
• active transport requires energy it is the movement of molecules from an area of low concentration to an area of high concentration against the concentration gradient
• diffusion helps the cell gain glucose oxygen and amino acids but get rid of waste such as co2 and urea (excess amino acids)
• if a plant cell is placed in a salt solution it will become plasmolysed but an animal cell will burst
• if a plant cell is placed in pure water it will become turgid but an animal cell will burst