1. Cellular Transport Across the Membrane

2. Let’s Remember the Cell Membrane

3. Sometimes a concentration gradient is created around the cell membrane.
A concentration gradient is the difference in the concentration of a substance from one location to another

4. There are two types of transport across the cell membrane
Passive Transport: Moves molecules from an area of high concentration to low concentration.
Active Transport: Molecules move from an area of low concentration to high concentration

5. Passive Transport is the movement of molecules across a cell membrane without energy input.
It is the movement of molecules from an area of high concentration to low concentration. It is also known as DIFFUSION.

6. Molecules will continue to move until they have reached equilibrium, or a balance on both sides of the membrane.
Molecules that diffuse across the cells membrane are small and nonpolar

7. Osmosis is a form of diffusion
Osmosis is the diffusion Of water

8. Cells can have many relationships with the solutions around them.

9. Isotonic Solution

10. In a hypertonic solution, water will exit the cell causing it to shrivel.

11. In a hypotonic solution, water will enter the cell and cause it to swell.

13. Facilitated Diffusion
Facilitated diffusion is the diffusion of molecules into a cell using membrane proteins.

14. The different types of active transport are: Endocytosis Exocytosis
Remember: Active transport moves molecules from an area of low concentration to high using chemical energy
The different types of active transport are:
Endocytosis
Exocytosis

15. Endocytosis is the process of taking liquids or fairly large molecules into a cell by engulfing them in the membrane.
Cells make a pocket around a substance
The pocket will break off inside of the cell and form a vesicle
The vesicle will fuse with a lysosome and be digested.
The substance is released into the cell.

16. Phagocytosis is a form of endocytosis
In phagocytosis, large molecules are engulfed into the cell.

17. Exocytosis is the opposite of endocytosis
Substances in the cell are enclosed in vesicles.
Vesicles will fuse with the cell membrane and release it’s contents on the outside of the cell.