1. Microscope Men
Robert Hooke
Antonie von Leeuwenhoek -1675

2. The Cell
Theory
Matthias Schleiden
Theodor Schwann
Rudolf Virchow

3. The Cell Theory Living things are made up of cells.
The cell is the basic unit of life.
All cells come from pre-existing cells by division.
Cells contain DNA which is passed from cell to cell during cell division.
All cells are basically the same in chemical composition.
All energy flow (metabolism & biochemistry) of life occurs within cells.  

4. Singer & Nicholson 1976
The Cell Membrane a.k.a
“Fluid Mosaic” Model

6. CO2 O2 Small molecules Small molecules that can cross CM freely.
Crossing the Membrane
CO2 O2
Small molecules
Small molecules that can cross CM
freely.

7. Diffusion
Concentration gradient – different between concentration of one molecule in one area vs. another.
Diffusion occurs down a concentration gradient.

8. Osmosis
In cells, osmosis is the diffusion of water across a cell membrane.

12. Turgor Pressure vs. Plasmolysis

13. Turgor Pressure vs. Plasmolysis

16. Turgor Pressure vs. Plasmolysis

17. Turgor Pressure vs. Plasmolysis

18. Facilitated diffusion
Passive Transport
No energy required
Occurs “down” the concentration gradient

19. Diffusion & Osmosis are examples of passive transport
Facilitated diffusion makes use of carrier proteins

20. Active Transport
Moving against the concentration gradient
Going from low concentration to high
Energy is needed to transport molecules.
Involves carrier proteins

22. Bulk Transport
Many macromolecules are too large to be transported by carrier proteins.
They are transported in or out of the cell by means of vesicle formation

23. Phagocytosis – “cell Eating”
Endocytosis
Phagocytosis – “cell Eating”

24. “Cell drinking”

28. Why are cells so small? Volume is how much room we have –
so we can fill all that space with food
coming in or waste going out.
Surface area is how much room we
have to move items in and out.
The bigger the cell, the more waste it
produces and food it needs, but the less
it can move those substances across
the membrane