1. Chapter 2, Lesson 3 Moving Cellular Material
How do materials enter and leave cells?
How does cell size affect the transport of materials?

2. Lesson 3 Vocabulary Passive transport Diffusion Osmosis
Facilitated diffusion
Active transport
Endocytosis
exocytosis

3. Quick Review of properties of the Cell Membrane
Forms the boundary between cells and between organelles
Controls the movement of substances into and our of cells
How it does this depends on:
Physical properties of the substance passing through
Chemical properties of the substances passing through
Semipermeable – will allow only certain substances to enter or leave a cell

4. Transporting Substances happens in 2 main ways:
I. Passive Transport
II. Active Transport
The movement of substances through a cell membrane WITHOUT USING THE CELL’S ENERGY
The movement of substances through a cell membrane only BY USING THE CELL’S ENERGY

5. I. Passive Transport
When can a cell move substances across the cell membrane using passive transport?
1. If the molecules are small
2. When there are MORE molecules of a substance on one side of the membrane than on the other side

6. Types of Passive Transport
Diffusion – the movement of substances from an area of higher concentration to an area of lower concentration
Osmosis – the diffusion of WATER molecules through a membrane
Facilitated Diffusion – when molecules pass through a membrane using special proteins called transport proteins

7. Assignment for tomorrow:
Read pages Label and answer the following questions in your notebook. Please write in complete sentences and re-state the questions.
VC-p. 62
RC-p. 63
KCC-p. 64
KCC-p. 65

11. The water on the right side would remain clear.
“What would the water in the beaker on the right look like if the membrane did notlet anything through?” VC-p. 62
The water on the right side would remain clear.
Think about these questions:
How would you describe the concentration of red dye molecules on each side of the membrane in the first beaker?
Why did the dye molecules move into the right side of the beaker?
What would the beaker look like if there was another picture taken after 60 minutes? Why?

12. “How do materials move through the cell membrane in facilitated diffusion?” RC-p. 63
Transport proteins called channel proteins and carrier proteins move materials through the cell membrane in facilitated diffusion.

13. Facilitated Diffusion
Used when molecules are too large or chemically unable to travel through a cell membrane
Does NOT require cell to use energy
Transport proteins are used to get the molecules across
Two types of transport proteins
Carrier proteins
Channel proteins

14. 2 Types of Transport Proteins
Carrier Proteins – “think ferry boat”
Channel Proteins – “think tunnel”
Carry large molecules through the cell membrane
Form pores through the cell membrane

15. II. Active Transport
The movement of substances through a cell membrane only BY USING CELL’S ENERGY
Second way materials can pass into or out of a cell
Used when moving substances from areas of LOWER CONCENTRATION TO HIGHER CONCENTRATION

16. 2 Types of Active Transport
Endocytosis
Exocytosis
The process during which a cell takes IN a substance by surrounding it with the cell membrane
The process during which a cell’s vesicles release their contents OUTSIDE the cell

17. “How do materials enter and leave cells?” KCC-p. 64
Materials enter and leave cells through the cell membrane using either PASSIVE TRANSPORT, such as diffusion, osmosis or facilitated diffusion; OR ACTIVE TRANSPORT, including endocytosis and exocytosis.

18. “how does cell size affect the transport of materials?” KCC-p. 65
As a cell becomes larger, its volume increases faster than its surface area, making the transport of enough materials to support the cell more difficult.

19. Milk can be easily transported in this picture
As the size of the community grows, it gets much harder to transport milk to the whole community

20. By splitting up the community, milk can, once again, be transported efficiently