1. Moving Cellular Materials
Honors Biology

2. Fluid Mosaic Model:
A mosaic is a structure made up of many different parts.
The plasma membrane of a cell is composed of different kinds of macromolecules.

3. Phospholipid bilayer

5. Passive Transport:
PASSIVE TRANSPORT- DOES NOT require energy to move materials through the cell membrane

6. 3 types of passive transport
Diffusion
Osmosis
Facilitated diffusion

7. 1. DIFFUSION- molecules of a substance will move from an area of high concentration to an area of low concentration, down the concentration gradient, until they reach equilibrium

8. Diffusion occurs in cells when substances (O2,CO2, salts, sugars, amino acids) that are dissolved in H2O move from an area of higher concentration to an area of lower concentration.

11. DIFFUSION

12. Osmosis
2. OSMOSIS (diffusion of water)-the movement of water molecules through a semi-permeable membrane from an area of greater water concentration or pressure to an area of lesser water concentration or pressure down the concentration gradient

13. OSMOSIS

14. 3 Types of concentration involved in osmosis
Hypertonic- too much solute, not enough water; if a cell is placed in this solution, cell will shrink & wrinkle
Hypotonic- too much water, not enough solute; if a cell is placed in this solution, cell will swell up, expand
Isotonic- equal parts water and solute; water moves in & out of the cell in dynamic equilibrium

16. OSMOSIS

17. 3 Types of Passive Transport: OSMOSIS

18. Facilitated diffusion
3. FACILITATED TRANSPORT- requires transport proteins in the cell membrane to move materials into and out of the cell either because the molecules that are transported are too big or they are polar (act against the nonpolar fatty acid tail of the lipid bilayer)

19. FACILITATED TRANSPORT

20. Factors that affect diffusion
Temperature – The rate of diffusion increases with the increase of temperature
Pressure- when pressure increases the rate of diffusion increases
Concentration – the rate of diffusion is effected by the concentration of the substances. It always takes place from higher to lower concentration.

21. Active Transport:
ACTIVE TRANSPORT- requires ENERGY, ATP, to move materials through the cell membrane
Work against concentration gradient
Molecules move from low to high concentration

22. Active Transport:

23. 3 Types of Active Transport:
ENDOCYTOSIS- requires ENERGY to move materials INTO the cell membrane
EXOCYTOSIS- requires ENERGY to move materials OUT OF the cell membrane
Ion pumps – Sodium –potassium pump and proton pumps

24. Active Transport:

25. Active Transport:

26. Active Transport:

27. through sodium potassium pumps.
This is an example of
Active Transport
through sodium potassium pumps.
Here sodium is taken outside of the cell, and potassium is brought inside the cell against concentration gradient.