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

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

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

Types of Cells VIRUS Not alive Has DNA but no organelles

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

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

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

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

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

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

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

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

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

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

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.

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

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

Why are Viruses Bad?

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

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!