<p> Chapter 3 Virtual Investigations Transport Across Cell Membranes</p><p>Directions: On your device desktop, Select the following (Repository, Science, Biology Virtual Investigations, Biology Virtual Investigations, Cell Biology)</p><p>Select: Transport Across Cell Membranes</p><p>1. What is the cell membrane composed of?</p><p>2. What are the two areas of the cell membrane?</p><p>3. What does polarity affect?</p><p>4. What portion of the cell membrane is polar?</p><p>5. What portion of the cell membrane is nonpolar?</p><p>6. What is embedded in the cell membrane?</p><p>7. What does the cell membrane do?</p><p>8. What types of things affect the amount of energy needed?</p><p>9. What substances can move or be actively transported through the cell membrane?</p><p>10. What is a concentration gradient?</p><p>11. What is diffusion?</p><p>12. What is passive transport?</p><p>13. How do polar molecules and ions repelled by the nonpolar interior of the phospholipid bilayer get across the cell membrane?</p><p>14. What is osmosis? 15. What is the charge of water?</p><p>16. What do carrier proteins do?</p><p>17. What happens when the substance fits into the binding site?</p><p>18. Give two examples of polar substances that diffuse through carrier proteins?</p><p>19. What is active transport?</p><p>20. What does active transport require?</p><p>21. What is one of the most important membrane pumps in animal cells?</p><p>22. What direction are the substances moved using this pump?</p><p>23. How many of each substance is moved through the membrane?</p><p>24. What is endocytosis?</p><p>25. What is exocytosis?</p>