AP Bio

1. Passive Transport – Movement of molecules across a membrane without energy, from high to low concentration.

2. Active Transport – Movement of molecules using energy (ATP), from low to high concentration.

3. Facilitated Transport (Facilitated Diffusion) – Passive movement of molecules with the help of a transport protein.

4. Endocytosis – Cell process that brings materials into the cell by forming vesicles.

5. Exocytosis – Cell process that releases materials out of the cell using vesicles.

6. Receptor-Mediated Endocytosis – A specific type of endocytosis where receptors bind to molecules before bringing them into the cell.

7. Pinocytosis – “Cell drinking”; the cell takes in fluids and small molecules.

8. Phagocytosis – “Cell eating”; the cell engulfs large particles or microorganisms.

9. Tonicity – How the concentration of solutes outside a cell affects water movement.

10. Isotonic – Solution with equal solute concentration inside and outside the cell → no net water movement.

11. Hypotonic – Solution with lower solute concentration outside the cell → water enters cell, causing swelling.

12. Hypertonic – Solution with higher solute concentration outside the cell → water leaves cell, causing shrinking.

13. Osmosis – The diffusion of water across a selectively permeable membrane.

14. Simple Diffusion – Passive movement of small, nonpolar molecules directly across the membrane.

15. High Concentration – A region where many molecules or solutes are present.

16. Low Concentration – A region where fewer molecules or solutes are present.

17. Concentration Gradient – The difference in concentration across a space or membrane.

18. Electrogenic Pump – A transport protein that moves ions and creates a charge difference across a membrane.

19. ATP (Adenosine Triphosphate) – The cell’s energy currency, used to power active transport and other processes.

20. Transport Protein – A protein in the membrane that helps substances move across (channels, carriers, pumps).