Cells and Cellular Transport

1. Cells and Cellular Transport S7L2a Explain that cells take in nutrients in order to grow and divide and to make needed materials

2. Characteristics of ALL Living Things • Cells • Sensitivity to stimuli • Growth • Homeostasis (stable internal environment) • Reproduction • Metabolism (transformation and use of energy) • Adaptation

3. Cell Theory • The Cell is the basic structural and functional unit of all organisms. • Cell Theory states three things: • All living things are made of cells • All cells come from other living cells of the same kind • Cells are the basic unit of all living things

4. Transport of Cell Material • Passive transport –Molecules move through plasma membrane from areas of higher concentration to areas of lower concentration • Spontaneous • No energy required • Two types • Diffusion • Osmosis

5. Process by which substances move from areas of higher concentration to areas of lower concentration

6. Movement of water through a semi-permeable membrane from an area of high water concentration to an area of low water concentration • Semi-permeable means it prevents some molecules from crossing. Think of osmosis as the diffusion of water when only water can get through the semi-permeable membrane

8. Active Transport • Not spontaneous • Cell must use stored energy to move substances across the cell membrane in the opposite direction of concentration • Example • Using active transport, a cell will move dissolved substances from an area of lower concentration to an area of higher concentration • Opposite of diffusion, therefore requires energy

9. Exocytosis • Type of active transport in which materials are discharged out of a cell • Opposite is endocytosis, which is a type of active transport in which substances are imported INTO the cell.