1. How substances move into and out of cells
Cell Transport
How substances move into and out of cells

2. What types of things need to get in & out of cells?
Organic compounds lipids, proteins, & carbohydrates)
Water
Cellular waste (CO2, ammonia)
Solutes/inorganic molecules (salts, vitamins, minerals)
How do these things get
across the cell membrane?

3. Cell Membrane
Composed of a lipid bilayer (two-layered) embedded with proteins
The cell membrane is selectively permeable or semi-permeable: some things can pass freely through it while others cannot

4. Internal & External Cell Environment
Every cell is filled with water and solutes (cytoplasm) and surrounded by water and solutes
Solute: Substance that is dissolved in a liquid
Solutes includes both organic compounds (fats, proteins, amino acids, starches) and inorganic compounds (salt, vitamins, minerals)
Water and solutes cross the cell membrane

5. Two ways a cell transports substances across its membrane

6. Passive Transport
Movement of substances across membranes without adding energy
Substances naturally move from areas of HIGH to LOW concentration
Small particles/water go through the lipid bilayer
Larger particle go through protein channels

7. Two types of passive transport

8. Tonicity
Comparison of solute concentration inside and outside the membrane
Hypertonic- the area with the higher concentration of solute
Hypotonic- the area of lower solute concentration
Isotonic- equal concentration of solutes

9. Hypertonic Outside

10. Hypotonic Outside

11. Isotonic

12. Equilibrium/Homeostasis
Occurs when the concentration of a substance is the same across an area
Dynamic Equilibrium: Even though substances are equal in concentration on either side of the membrane, they continue to move back and forth.

13. Active Transport
When the cell must use energy (ATP) to get substances across the membrane
Movement of substances from LOW to HIGH concentration levels
Movement of large particles

14. Three ways cells move large particles in and out:

15. Phagocytosis- Extensions of cytoplasm wrap around and engulf large particles

16. Endocytosis- Cell pinches off membrane bound packets into cell Exocytosis- Cell expels membrane bound packets out of cell

17. Finger Mini-Lab
Question: After soaking two fingers in fresh water and two fingers in salty water for 15 minutes, how will they look different?
Hypothesis:
If I soak my fingers in salty water, they will look _____.
If I soak my fingers in fresh water, then they will look _____.
Conclusion: Were you hypotheses right? Explain the results, using the following words:
Hypertonic, hypotonic, osmosis, diffusion, solute