Cellular Transport and the Cell Cycle

1. Cellular Transport and the Cell Cycle Unit 3 Chapter 8

2. Different ways of transporting materials across a cell membrane Passive transport Diffusion Osmosis: water diffusion Facilitated transport Active transport Exocytosis Endocytosis

3. Cells in isotonic solutions Cell loses and gains water at an equal rate. Net change to cell = nothing

4. Isotonic solution Not ideal for plant cells because the cells become flaccid (limp) Ideal for animal cells or cells without cell walls

5. Cells in a hypotonic solution More water moves into the cell than moves out. Net change = cell mass increases

6. Hypotonic solution Ideal for plant cell where the cell becomes turgid (swollen) Not ideal for animal cells where the cell lyses (bursts)

7. Cells in a hypertonic solution More water moves out of the cell than moves in Net change = cell mass decreases

8. Hypertonic solution Not ideal for any cell Both shrink.

9. Passive transport Movement of materials across a cell membrane in the direction of higher concentration to lower concentration No ATP energy required

10. Passive transport by proteins Facilitated transport Movement of chemicals down a chemical gradient (from high to low concentration) through a protein

11. Passive transport

12. Channel vs. carrier proteins