This document discusses cell transport mechanisms like diffusion and osmosis. It aims to explain the differences between diffusion, osmosis, and active and passive transport. Passive transport mechanisms like diffusion and osmosis involve molecules moving across membranes down concentration gradients without cellular energy input. Diffusion is the spontaneous spread of molecules from high to low concentration, while osmosis specifically refers to the diffusion of water molecules across semipermeable membranes.

1. Science SMART Board
King Faisal School
Cell Structure and Function
‘Diffusion & Osmosis’
Created by: Hamdy Karim
Grade level(s): 9th_Grade
Subject area: Biology

2. Diffusion & Osmosis
Objectives;
Students will be able to
answer the questions;
1. What is the difference between
Diffusion & Osmosis?
2. What are the types of Cell
Transport?
3. What is the difference between
Active Transport and Passive
Transport?
Done By:
Mr. Hamdy Karim
KFS, Riyadh, KSA.
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3. KEY CONCEPT Materials move across membranes
because of concentration differences.
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4. Passive transport does not require energy input from a
cell.
• Molecules can move across the cell membrane
through passive transport.
• There are two types of
passive transport.
• osmosis
• diffusion
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5. Diffusion and osmosis are types of passive
transport.
• Molecules diffuse down a
concentration gradient.
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6. Diffusion and osmosis are types of passive
transport.
• Osmosis is the diffusion of water molecules across a
semipermeable membrane.
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7. Diffusion and osmosis are types of passive transport.
• There are three types of solutions.
• isotonic
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• hypotonic
• hypertonic

8. Some molecules can only diffuse through transport
proteins.
• Some molecules cannot easily diffuse across the cell
membrane.
• Facilitated diffusion is
diffusion through transport
proteins.
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