1. Cellular Transport Notes
Homeostasis, Passive Transport, Diffusion, Osmosis, & Active Transport

2. Learning Questions
How do cells maintain homeostasis in changing environments?
How do cells take in nutrients in order to grow and divide and to make needed materials?
How do you explain the relationship between the structures and functions of cell organelles?

3. Get Ready to take notes!

4. Objective of the Unit Explain that cells need to maintain homeostasis
Explain passive transport and diffusion
Define the process of osmosis
Explain the process of active transport and the role of ATP
Explain the processes of endocytosis and exocytosis

5. CELLS AND THEIR ENVIRONMENT:
HOMEOSTASIS

6. LIFE’S BALANCING ACT
If you are too hot or too cold your body temperature is out of balance

7. 2 examples of homeostasis
When we are too cold we shiver, it warms us up
When we are too hot we sweat, it cools us down.
2 examples of homeostasis

8. Sweating and shivering are the body’s response to extreme temperature.
They help the body return to a temperature that is comfortable.
Sweating and shivering are the body’s response to extreme temperature.
The body is balanced

9. HOMEOSTASIS
The balance that all living things must maintain is called HOMEOSTASIS.

10. Importance of CELL BALANCE
Your body is made up of cells that must stay balanced. They need the right amount of materials to maintain the proper environment for your body.

11. Objective of the Unit Explain that cells need to maintain homeostasis
Explain passive transport and diffusion
Define the process of osmosis
Explain the process of active transport and the role of ATP
Explain the processes of endocytosis and exocytosis

12. Concentration Gradient:
The difference between the regions of high concentration and low concentration
The steeper the concentration gradient, the faster diffusion takes place
High concentration gradient
Fast rate of diffusion
Low concentration gradient
Slow rate of diffusion

13. “Selectively Permeable” Membranes
“Semi-Permeable” or
“Selectively Permeable” Membranes
A semi-permeable membrane will allow certain molecules to pass through it, but not others.
Partially permeable membrane
Generally, small particles can pass through…
…but large particles cannot

15. Cellular Transport!
The process by which molecules move from one side of the cell membrane to the other
Two Types Include:
Passive
Active

16. Passive Transport

17. Passive Transport Two Types Include: Doesn’t require energy
Molecules move from high to low concentration Analogy: Like coasting down hill on a bike!
Two Types Include:
Diffusion
Osmosis

18. Diffusion
The passive movement of MOLECULES along a concentration gradient, or from regions of high to low concentration. EX: Spraying air freshener

19. Diffusion occurs because the particles in gases and liquids are moving.

20. Diffusion Particles in a liquid or gas spread out…
… from regions of high concentration…
… to regions of low concentration…
…until the particles are evenly spread out.

21. Osmosis- A type of diffusion
Osmosis is the DIFFUSION of WATER molecules…
… from a region of high concentration to low concentration …across a semi-permeable membrane…
…until they are evenly spread out.

22. Passive Transport Does osmosis or diffusion require energy?
No, molecules move along a concentration gradient
(high to low).

25. Free water molecules diffuse in this direction
Partially-permeable membrane
More free water molecules on this side of membrane
Water-solute particle is too large to pass through membrane
Free water molecules diffuse in this direction

28. TOD: Complete the definition
Osmosis is the movement of water
molecules from a region of high
concentration to low concentration
across a semi-permeable membrane.
answer

29. Brain Pop- Diffusion

30. Mind Stretcher 12-7-17 Endocytosis: Exocytosis:
Draw a simple diagram of the 2 active transport processes:
Endocytosis:
Exocytosis: