The Cell in Its Environment Outline Notes

1. The Cell in Its Environment Outline Notes

2. Prediction: Please write a prediction of what YOU think the text will be talking about.

3. I. Diffusion Talk to the Text Can all molecules move? Or just some of them? What does high concentration and low concentration mean? • Diffusion is the main method by which small molecules move across the cell membrane. • Diffusion- process where molecules move from an area of higher concentration to an area of lower concentration

4. A. What Causes Diffusion? Talk to the Text What causes diffusion? So the molecules act like bouncy balls that bounce around till they are no longer touching one another • molecules move around and collide into each other causing them to spread evenly throughout an area

5. B. Diffusion of Oxygen Talk to the Text How is oxygen involved in diffusion? oxygen is one of the molecules that can move through a membrane • oxygen will diffuse from the area of high concentration to low concentration until they are evenly spread

6. II. Osmosis Talk to the Text What is a selectively permeable membrane? • Osmosis- diffusion of water molecules throughout a selectively permeable membrane • Because cells cannot function properly without adequate water, many cellular processes depend on osmosis.

7. A. Osmosis and Diffusion Talk to the Text What is the difference between osmosis and diffusion? so osmosis is the movement of water only and diffusion is the movement of molecules only • water molecules move from an area of high concentration to low concentration

8. B. Effects of Osmosis Talk to the Text What are the effects of osmosis? • a blood cell in water with lots of salt will shrink • a blood cell in water with little salt will swell

9. III. Active Transport Talk to the Text What is active transport? if passive transport doesn’t require energy, then diffusion and osmosis must be examples of it • Passive Transport- movement of dissolved materials through a membrane without using cellular energy • Active Transport- movement of materials through a membrane using cellular energy • Active transport requires the cell to use its own energy, while passive transport does not.

10. A. Transport Proteins Talk to the Text What are transport proteins? transport proteins are channels in the cell membrane • transport proteins “pick up” molecules outside the cell and bring them in using energy

11. B. Transporting by Engulfing Talk to the Text What is engulfing? Is engulfing kinda like eating? • cell membrane surrounds and engulfs a particle to form a vacuole

12. C. Why Cells Are Small Talk to the Text Why are cells small? How does a cell stop becoming too big? • as a cell’s size increases it can no longer function

13. What did I learn today?: Please write a statement describing something that you learned from today’s lesson.