| A | B |
|---|
| cell functions | must be able to obtain energy and raw materials and get rid of wastes |
| importance of cell functions | keep cells healthy so they can grow and repair injuries |
| cell membrane | the place where exchange of materials between a cell and its environment happen |
| diffusion | the main method by which substances move into and out of cells |
| how diffusion works | particles tend to move from an area of high concentration to an area of low concentration |
| passive transport | the movement of particles across a cell membrane without using energy |
| kinds of passive transport | diffusion & osmosis |
| osmosis | the movement of water molecules through the cell membrane |
| semipermeable | it means that only certain substances can pass through the cell membrane while others cannot |
| active transport | the movement of particles across a cell membrane using energy |
| how active transport works | usually the movement of particles from an area of low concentration to an area of high concentration |
| endocytosis | the process by which a cell surrounds a large particle and encloses it in a vesicle to bring the particle into the cell |
| exocytosis | the process by which a vesicle forms around a large particle within the cell and carries the particle to the cell membrane to release it |
| vesicle | sacs formed from pieces of cell membrane |
| diffusion activities | eggs & vinegar; iodine and starch; air freshner |
| osmosis activities | food coloring; potatoes & salt; roots of plants |
