How is material transported into and out of the cell? Cell Transport How is material transported into and out of the cell?

Cell Transport in the Garden As you observe and illustrate your plants, think about how water and minerals enter the plant. Write you ideas on the space provided.

Describe how we move through out the classroom. Class Activity Describe how we move through out the classroom.

Class Activity Recap The students moved from an area of high/low concentration or density to an area of high/low concentration until ________________________ is reached.

Cell Membrane The cell membrane regulates what substances can enter and exit the cell. It is referred to as “selectively permeable.” THINK! - What does selective mean? Very Choosy THINK! - What does permeable mean? To pass through Substances that can easily pass through the cell membrane are oxygen, carbon dioxide, and water. However, other substances such as salts and large sugar molecules can not easily pass through. Substances can move into and out of the cell by either passive transport or active transport. Passive transport does NOT require energy. Active transport requires energy.

Perfume Demo Raise your hand when you smell the perfume! THINK! - How were the people in the back of the room able to smell the perfume?

Food Dye Demo Observe the food coloring as it is dropped into the beaker of water. THINK! - What happened to the food coloring particles?

Passive Transport You just observed 2 examples of diffusion. Now, turn to your neighbor and try to define the term “diffusion.” Diffusion: the movement of molecules from an area of HIGH concentration to an area of LOW concentration without using energy. The molecules will continue to move until they spread out evenly. This is called equilibrium. THINK! - Can you come up with any other examples?

Diffusion Animation Cells obtain certain particles through diffusion. For example, small oxygen molecules can easily pass through the cell membrane. Check out these 3 animations!! How Diffusion Works http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html Perfume Diffusion http://www.biosci.ohiou.edu/introbioslab/Bios170/diffusion/Diffusion.html Diffusion with arrows http://www.indiana.edu/~phys215/lecture/lecnotes/diff.html

Lab Observations Why did this happen? Object Prediction for water Result for water Prediction for saltwater Results for saltwater Raisin Carrot Potato Gummy bear Why did this happen?

Passive Transport Just like oxygen and other small particles can diffuse into and out of cells, water can also diffuse!! THINK! - Can you define osmosis? Osmosis: the movement of water molecules from an area of HIGH concentration to an area of LOW concentration without using energy. The molecules of water will continue to move until they spread out evenly.

Raisin Demo THINK! - Using what you know about osmosis, what will happen to these raisins if I drop them in a beaker of water? Let’s make a hypothesis!

Osmosis Problems Problem #1 – A cell is placed in water that contains a little bit of salt. Therefore, the concentration of water is higher in the beaker compared to the inside the cell. Which way will the water flow? ANSWER: Water will flow into the cell; the cell will swell

Osmosis Problems Problem #2 – A cell is floating in water that contains a lot of salt. Thus, the concentration of water in the beaker is low compared to the inside of the cell. Which way will the water flow? ANSWER: Water will flow out of the cell; the cell will shrink

Osmosis Problems Problem #3 – A cell is floating in fresh water. Thus, the concentration of water in the beaker is the same as the concentration of water inside of the cell. Will water move into or out of the cell? ANSWER: Water molecules will flow into and out of the cell at an equal rate; the cell shape will remain the same

How would you explain this cartoon using your knowledge of osmosis?

Active Transport Active Transport: the movement of particles from an area of LOW concentration to an area of HIGH concentration with the use of energy. Active Transport is like pedaling a bike uphill. Its takes a lot of energy. THINK! - How is active transport different from passive transport? Active transport requires energy while passive transport does not. **LOW to HIGH**

Osmosis in Elodea cells Fresh Water Salt Water