1. Unit 3 Mallard Creek Biology
Cellular Transport
Unit 3
Mallard Creek Biology

2. Evolution of the Plasma Membrane…
The formation of a membrane that encloses a solution different from the surrounding solution while still permitting the uptake of nutrients and the elimination of waste products was a key event in the evolution of life.
The ability of the cell to discriminate in its chemical exchanges with its environment is fundamental to life.

3. Plasma Membrane
The plasma membrane is responsible for helping to maintain the homeostasis of a cell.
Selective permeability- a process in which a membrane allows some ions and molecules to pass through while keeping others out.

5. Primary components Recall the main components of the plasma membrane:
Lipids
Proteins
Carbohydrates

7. Transport through the plasma membrane
Extracellular fluid- the fluid that surrounds cells.
The main component is interstitial fluid.
Intracellular fluid- the fluid inside of a cell.
Also called the cytosol.

8. Passive Transport
Passive transport - movement of materials through the cell membrane that does not require the use of energy
Diffusion- The movement of particles from an area of high concentration to low concentration
Osmosis- The diffusion of water through a semi-permeable membrane. In the case of cells, this will be the plasma membrane.

9. Diffusion- passively high to low

10. Osmosis- movement of water

11. Extracellular Fluid
Intracellular Fluid

12. Extracellular Fluid
Intracellular Fluid

14. 3 types of solutions: Hypertonic- concentration
of dissolved materials is
greater in the extracellular
fluid than it is in the
intracellular fluid.
Plasmolysis- cell shriveling
due to a decrease in internal pressure

15. 3 types of solutions: Isotonic- concentration
of dissolved salts in the
intracellular fluid is the
same as it is in the
extracellular fluid.
there is no osmotic
gradient
water will not move in
any one particular direction

16. 3 types of solutions: Hypotonic- concentration
of dissolved materials in the
intracellular fluids is greater
than that in the extracellular
fluid.
Cytolysis- cell bursting due
to internal pressure

19. What if you live in a hypotonic environment?
Contractile vacuole- a special organ in protists that pumps water out.
Protists- unicellular, freshwater organisms.

20. Active Transport
Active transport- requires the use of cell energy (ATP)as a substance is moved against its concentration gradient.

21. Endocytosis- process by which cells take in materials
Phagocytosis- “cell eating”; engulfing solid particles
Pinocytosis- “cell drinking”; engulfing liquid particles

23. Amoeba
Pseudopod- “false foot”

24. Exocytosis- process by which cells excrete wastes and other large molecules
Secretion- process of elaborating, oozing, or releasing chemicals or chemical substances
Excretion- waste products or by products

25. Blood
Blood- specialized bodily fluid that functions to transport substances throughout the body
RBCs - Contains hemoglobin, an iron based protein that transports oxygen.
Plasma - Extracellular fluid around blood cells. It is a clear yellow fluid that transports nutrients from digestive system to rest of the body.

26. Problems
Plasma contains 15% glucose, and intestine cell contains 10% glucose. Which direction will glucose move?
RBC contains 30% oxygen, and liver cell contains 10% oxygen. Which direction will oxygen move?

27. Review
The plasma membrane is said to be selectively permeable. Describe what this means.
Define passive and active transport.
Differentiate between diffusion and osmosis, endocytosis and exocytosis, and pinocytosis and phagocytosis.
Of the above, which are active and which are passive?

28. Review- Determine which way the water will move.1.
10%
NaCl
60%
H2O

29. Review- Determine which way the water will move.2.
40%
NaCl
10%
H2O

30. Review- Determine which way the water will move.3.
80%
H2O
10%
NaCl

31. Review- Determine which way the water will move.4.
20%
H2O
100%

32. Review- Determine which way the water will move.5.
20%
NaCl
30%

33. Hypertonic, Isotonic, Hypotonic?