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Questions

1. What is passive transport?

2. What is diffusion?
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3.What 3 factors is diffusion affected by?
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4. What is osmosis?
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5. Draw a picture explaining osmosis.
 6. Define the following: isotonic solution, homeostasis, hypotonic
solution, hypertonic solution.
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7. What would happen to a cell placed in a hypotonic solution? What
about a hypertonic solution?
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8. What is active transport?
1. What is passive transport?
 Materials moving across a cell membrane without
energy.
2. What is diffusion?
 Movement of molecules from high concentrations to
low concentrations.
 Eg: Diffusion of oxygen into an aerobically respiring
cell.
 The cell is using oxygen as it respires. The use of
oxygen creates a lower concentration of oxygen inside
the cell than outside of it. The cell gets more oxygen
through diffusion, as oxygen goes from an area of
higher concentration (outside the cell) to an area of
lower concentration (inside the cell)
How are Passive Transport
and Diffusion Related?
 As diffusion is defined as 'the net movement of
particles from an area of higher concentration to an
area of lower concentration' and the fact that
molecules of oxygen are small enough to pass freely
through a cell membrane, the movement requires no
energy, and is therefore passive.
3.What 3 factors is
diffusion affected by?
 Temperature, pressure, and concentration.
 https://www.youtube.com/watch?v=A-5S2e1ubT8
 https://www.youtube.com/watch?v=CNP-dCQ-Cmg
4. What is osmosis?
 The diffusion of water across a selectively permeable
membrane.
5. Draw a picture
explaining osmosis.
6. Define the following: isotonic solution,
homeostasis, hypotonic solution, hypertonic solution.

Isotonic solutions- solute concentration outside a cell is equal to the
concentration inside the cell.

Homeostasis- Having a constant internal environment

Hypotonic solution- A solution that has lower concentration of solute
and higher concentration of water compared to the cell.

Hypertonic- A solution that has a higher concentration of solute and
lower concentration of water compared to the cell.

http://www.youtube.com/watch?v=_slUL3kMZlU&feature=related

http://www.youtube.com/watch?v=Zg-oa2xtblg
7. What would happen to a cell placed in a
hypotonic solution? What about a hypertonic
solution?
 If placed in hypotonic  Cell would grow
 If placed in hypertonic  Cell would shrink
 Hypotonic solutions can be used for treatment of
dehydration. Since the solute in hypotonic solutions is
less, water will shift from the solution into the cell. So
for a patient having dehydration, meaning there is less
water inside the cell, hypotonic solutions can be of
great help in correcting the deficiency by allowing
water to shift back into the cell.
8. What is active transport?
 Materials being moved across a cell membrane using
the energy of the cell
 https://www.youtube.com/watch?v=2-icEADP0J4
Eg: The thyroid gland cells bring in iodine for use in
producing hormones, but require energy to do so.
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