Download Name: ______ Pd ______ Date Foundations of Biology Mr

Name: __________________________
Foundations of Biology
Pd _______
Date______________
Mr. Thompson
Passive Transport Webquest
Diffusion thru Membrane
http://www.indiana.edu/~phys215/lecture/lecnotes/diff.html (Click on Diffusion with Arrows)
1. At the beginning of the animation, how many particles are on each side of the
membrane? A. Left side has _____________
B. Right side has ____________
2. The particles are moving in both directions, however more molecules from the left side
are moving to the ___________ side.
3. Watch the animation for 2 minutes, or until it reaches NO NET FLOW. How many
particles are on each side of the membrane?
4. When there is NO NET FLOW, the cell is said to reach what?
5. Diffusion is the movement of molecules from an area of higher concentration to an area
of lower concentration without the use of __________________.
Osmosis effects on the cell
http://www.tvdsb.on.ca/westmin/science/sbi3a1/Cells/Osmosis.htm
6. Cell membranes are semi-permeable. What does this mean?
Are cell membranes permeable to water?
7. The word “solute” has been used several times in this website. What do you think the
term “solute” means or refers to?
8. Press Play for Hypertonic: What happens to the cell in a hypertonic solution?
Why?
Why does water move this way?
9. Press Play for Hypotonic: What happens to the cell in a hypotonic solution?
Why?
Why does water move this way?
10. Press Play for Isotonic: What happens to the cell in an isotonic solution?
Why?
Why does water move this way?
http://programs.northlandcollege.edu/biology/Biology1111/animations/transport1.html
PART ONE: Choose PASSIVE TRANSPORT FIRST
11. Define PASSIVE TRANSPORT :
12. List the three types of passive transport: 1.
2.
3.
13. The cell membrane consists of several parts which include:
1. ___________ - may act as channels
2. Fluid _________ bilayer
14. Diffusion is the movement of molecules from an area of ______ concentration to an area of
_________ concentration.
15. Diffusion is said to move ______________ the concentration gradient.
16. There are 4 factors that influence the rate of diffusion.
1. The concentration gradient (The differences between molecules in a given space)
2. The charge of the molecule
3. The size of the molecule
4. ______________________________
16. Diffusion ends when equilibrium is reached. What does equilibrium mean?
17. Define facilitated diffusion:
18. Does facilitated diffusion take energy for the cell? _________
19. Does facilitated diffusion move down the concentration gradient? ___________
20. What helps the molecules move into and out of the cell during facilitated diffusion?
___________________________________________
21. Osmosis is the diffusion of _______________ across a cell membrane.
22. Hypertonic solutions have a ________________ amount of dissolved solute and therefore
less pure water.
23. Water tends to move towards the _________________ environment because the solute levels
are higher but the water concentration is lower.
24. Hypotonic solutions have _________________dissolved solutes but a higher concentration
of pure water.
25. Isotonic solutions have ____________ amounts of solute inside and outside the cell.