1. I. The Cell Membrane Gateway to the Cell
The Plasma Membrane
1/18/2019
I. The Cell Membrane
Gateway to the Cell
G. Podgorski, Biol. 1010

2. Photograph of a Cell Membrane
The Plasma Membrane
1/18/2019
Photograph of a Cell Membrane
G. Podgorski, Biol. 1010

3. A. What does it do? Surrounds the cell
The Plasma Membrane
1/18/2019
A. What does it do?
Surrounds the cell
Maintains homeostasis: controls what enters & leaves the cell (semi-permeable)
a. Hormones, food waste, etc
G. Podgorski, Biol. 1010

4. copyright cmassengale
The Plasma Membrane
1/18/2019
2. What is it made of?
copyright cmassengale
G. Podgorski, Biol. 1010

5. II. What is it made of? Phospholipids Proteins The Plasma Membrane
1/18/2019
II. What is it made of?
Phospholipids
Proteins
G. Podgorski, Biol. 1010

6. II. Types of Transport Across Cell Membranes
The Plasma Membrane
1/18/2019
II. Types of Transport Across Cell Membranes
G. Podgorski, Biol. 1010

7. Movement substances across a cell membrane:
A. Passive Transport
Movement substances across a cell membrane:
From HIGH to LOW amounts
(concentrations)
Uses NO energy

8. 1. Diffusion Requires NO energy
The Plasma Membrane
1. Diffusion
1/18/2019
Requires NO energy
Gasses and small molecules move from area of HIGH to LOW concentration
G. Podgorski, Biol. 1010

9. Diffusion of Food Coloring
The Plasma Membrane
1/18/2019
Diffusion of Food Coloring
G. Podgorski, Biol. 1010

10. Diffusion through a Membrane
The Plasma Membrane
1/18/2019
Diffusion through a Membrane
Cell membrane
Solute moves DOWN concentration gradient (HIGH to LOW)
G. Podgorski, Biol. 1010

11. Check for understanding
copyright cmassengale

12. 2. Osmosis Movement of water across a membrane
The Plasma Membrane
2. Osmosis
1/18/2019
Movement of water across a membrane
Moves from HIGH water amount (low solute) to LOW water amount (high solute)
High H2O amount Low solute concentration
Low H2O amount High solute concentration
G. Podgorski, Biol. 1010

13. a. Isotonic Solution The cell stays the same CELL 10% NaCL 90% H2O
The Plasma Membrane
1/18/2019
10% NaCL 90% H2O
ENVIRONMENT
CELL
NO NET MOVEMENT
10% NaCL
90% H2O
What is the direction of water movement?
The cell stays the same
G. Podgorski, Biol. 1010

14. b. HypOtonic Solution The cell will SWELL CELL 10% NaCL 90% H2O
The Plasma Membrane
1/18/2019
b. HypOtonic Solution
10% NaCL 90% H2O
CELL
20% NaCL
80% H2O
What is the direction of water movement?
The cell will SWELL
G. Podgorski, Biol. 1010

15. c. Hypertonic Solution The cell will SHRINK CELL 15% NaCL 85% H2O
The Plasma Membrane
1/18/2019
15% NaCL 85% H2O
ENVIRONMENT
CELL
5% NaCL
95% H2O
What is the direction of water movement?
The cell will SHRINK
G. Podgorski, Biol. 1010

16. NO NET MOVEMENT OF H2O (equal amounts entering & leaving)
The Plasma Membrane
1/18/2019
Isotonic Solution
Hypotonic Solution
Hypertonic Solution
NO NET MOVEMENT OF H2O (equal amounts entering & leaving)
CELL SWELLS
CELL SHRINKS
G. Podgorski, Biol. 1010

17. Osmosis in Red Blood Cells
The Plasma Membrane
1/18/2019
Osmosis in Red Blood Cells
Isotonic
Hypertonic
Hypotonic
G. Podgorski, Biol. 1010

18. 1. What type of solution is Cell A? 2. What will happen to cell A?

19. 3. Facilitated Diffusion
The Plasma Membrane
1/18/2019
3. Facilitated Diffusion
Doesn’t require energy
Uses transport proteins to move from an area of high to low concentration
Examples: Glucose or
amino acids moving
from blood into a cell.
G. Podgorski, Biol. 1010

20. Facilitated Diffusion
The Plasma Membrane
1/18/2019
Facilitated Diffusion
Molecules will randomly move through the pores in Channel Proteins.
copyright cmassengale
G. Podgorski, Biol. 1010

21. Facilitated Diffusion
The Plasma Membrane
1/18/2019
Facilitated Diffusion
Some Carrier proteins do not extend through the membrane.
They bond and drag molecules through the lipid bilayer and release them on the opposite side.
G. Podgorski, Biol. 1010

22. Facilitated Diffusion
The Plasma Membrane
1/18/2019
Facilitated Diffusion
Other carrier proteins change shape to move materials across the cell membrane
G. Podgorski, Biol. 1010

23. B. ACTIVE TRANSPORT

24. Active Transport Requires energy or ATP
The Plasma Membrane
1/18/2019
Active Transport
Requires energy or ATP
Moves materials from LOW to HIGH concentration
AGAINST the flow (concentration gradient)
G. Podgorski, Biol. 1010

25. Three Forms of Transport Across the Membrane
The Plasma Membrane
Three Forms of Transport Across the Membrane
1/18/2019
G. Podgorski, Biol. 1010

26. Check for understanding
Which Protein would be used?
What type of transport is this?

27. C. BULK MOVEMENT
Movement of BIG, BULKY molecules
Requires ENERGY

28. 1. EXOCYTOSIS- moving bulky things out of the cell.
The Plasma Membrane
1/18/2019
1. EXOCYTOSIS- moving bulky things out of the cell.
G. Podgorski, Biol. 1010

29. Exocytosis Inside Cell Cell environment The Plasma Membrane 1/18/2019
G. Podgorski, Biol. 1010

30. The Plasma Membrane
Exocytosis
1/18/2019
Exocytic vesicle immediately after fusion with plasma membrane.
G. Podgorski, Biol. 1010

31. ENDOCYTOSIS- Large molecules move into the cell.
The Plasma Membrane
1/18/2019
ENDOCYTOSIS- Large molecules move into the cell.
G. Podgorski, Biol. 1010

32. The Plasma Membrane
1/18/2019
ENDOCYTOSIS
G. Podgorski, Biol. 1010

34. ENDOCYTOSIS About to Occur
The Plasma Membrane
ENDOCYTOSIS About to Occur
1/18/2019
G. Podgorski, Biol. 1010

35. The Plasma Membrane
1/18/2019
Endocytosis- Capture of a Yeast Cell (yellow) by Membrane Extensions of an Immune System Cell (blue)
G. Podgorski, Biol. 1010