1. The Cell Membrane Cell Types
Science Review Week 2
The Cell Membrane
Cell Types

2. Types of Cells PROKARYOTE Flagellum A simple cell DNA floats free
Example: bacteria
Flagellum

3. Types of Cells EUKARYOTE A real cell DNA in the nucleus
Example: plant and
animal cells

4. Types of Cells
VIRUS
Not alive
Has DNA but no organelles

5. Don’t forget about viruses… We’re coming back!

6. The Cell Membrane Purpose: Controls what enters and leaves the cell.
Active Transport: on purpose
Passive Transport: just happens

7. Water
Water moves through the cell membrane passively. This is called Osmosis. Nature wants everything to be balanced Homeostasis – same state, balanced

8. Water
Water moves through the cell membrane passively. This is called Osmosis. Nature wants everything to be balanced Homeostasis – same state, balanced

9. Where is there more water? Which way will the water flow?

10. Where is there more water? Which way will the water flow?
Water Flows OUT Cell Shrinks

11. Where is there more water? Which way will the water flow?

12. Where is there more water? Which way will the water flow?
Water Flows IN Cell Swells

14. How do viruses get into a cell?
Viruses get in by active transport.
They trick the cell into letting them in.

15. Cell Membrane
The cell membrane has gates that let nutrients in… if they have the right key (receptor).

16. Viruses carry all of the as many different ‘keys’ as they can
Viruses carry all of the as many different ‘keys’ as they can. Hopefully one of them will match.

17. Will the virus be able to get into the cell?
CELL VIRUS

18. Will the virus be able to get into the cell?
YES!

19. Why are Viruses Bad?

20. Why are Viruses Bad?
Once inside, the virus DNA takes over and turns the cell into a slave that just makes more viruses.

21. Other things you need to know:
HIV/AIDS is a virus. It attacks T-cells. Antibiotics can kill bacteria Antibiotics do not work on viruses because viruses are not alive!