Cell Transport Study Guide 1. Why does diffusion occur? Kinetic energy causes molecules to constantly move and collide with each other. 2. What is the movement from an area of high concentration to an area of low concentration? Diffusion 3. Give the type of particle transport that requires input of energy from the cell. Active Transport 4. What happens to cells placed in a hypertonic solution? They shrink due to losing water by osmosis 5. Which parts will be near water because they are hydrophilic? Part labeled A:Polar heads of the phospholipids 6. Which parts will repel water because they are hydrophobic? Part E: Non Polar Tails of phospholipids 7. When the concentrations across a cell membrane are the same… Does Osmosis occur? No. Because the cell is at equilibrium in a state of homeostasis 8. Are cholesterol and phospholipids hydrophobic or hydrophilic? Hydrophobic. Both are repelled by water. 9. What is osmosis? The diffusion of water 10. What happens to a cell that is placed in a hypotonic solution? It swells up 11. What structure serves as the cell’s boundary from its environment and regulates which materials enter and leave the cell? Cell Membrane 12 Large molecules such as hormones are released or expelled from a cell during? Exocytosis 13. What happens if too much water diffuses into a cell? It may burst 14. What is an example of passive transport? Diffusion 15. What is passive transport? Cell transport that requires no energy from the cell 16. What is the movement of molecules down a concentration gradient across the cell membrane? Diffusion What is the difference in the concentration of dissolved particles from one location to another is called? Concentration Gradient