The document describes the fluid mosaic model of the cell membrane and different types of transport across the membrane. The cell membrane is a phospholipid bilayer that allows for both passive and active transport. Passive transport includes diffusion, osmosis, and facilitated diffusion, which move molecules down concentration gradients without energy. Active transport requires energy and transports molecules against concentration gradients using endocytosis, exocytosis, and ion pumps like the sodium-potassium pump.

1. Moving Cellular Materials SOL BIO 4.d

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.  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 (O 2 ,CO 2 , salts, sugars, amino acids) that are dissolved in H 2 O 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 effect 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 cocentration

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