1. Topic: Passive Transport Aim: How do certain molecules enter the cell?
Name____________________________________ Packet # 9: Passive Transport Instructions 1. Go to 2. Go to Living Environment Units->scroll to Unit 2-> select Transport 3. Download the Introduction to Transport powerpoint 4. Use the powerpoint to help you complete this worksheet.
Topic: Passive Transport Aim: How do certain molecules enter the cell?

2. Do Now!
Brainstorm: What parts of a house separate it from it’s external environment?
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What may enter through those parts?
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3. Which organelle controls substances entering and leaving the cell
Which organelle controls substances entering and leaving the cell? Cell Membrane
Controls movement in and out of the cell
Selectively permeable
Some substances can pass freely.
Some substances can pass to an extent.
Some not at all.
Allow cells to maintain homeostasis.

4. Structure of the Cell Membrane How does the structure of the cell membrane allow it to do its job?
The structure of the cell membrane is composed of
2 lipid (fat layers)
The head is hydrophilic (love water)
The tails are hydrophobic (hate it)

5. Phospholipids only let small molecules pass through
Phospholipids only let small molecules pass through. What are those small molecules? 1. oxygen 2. carbon dioxide 3. water 4. glucose

6. How can the larger ones get in the cell
How can the larger ones get in the cell? Proteins embedded in the cell membrane facilitate (aid) in this
Proteins allow only certain molecules pass by based on their shape.

7. Why do molecules move? Diffusion
Molecules are randomly moving
Collision of molecules
Molecules move from a high concentration to low concentration
This occurs because of a concentration gradient.
Diffusion only occurs if their is a concentration gradient.

8. Predict what will happen to the molecules inside the cell?

9. NET DIFFUSION STOPS WHEN EQUILIBRIUM IS REACHED.
Molecules will bump into each other as they move.
Eventually, the molecules will be evenly spread out.
Equilibrium: When there is an even concentration of molecules.
NET DIFFUSION STOPS WHEN EQUILIBRIUM IS REACHED.

10. Too large
to diffuse

11. Predict the movement of these molecules after 20 minutes later