Unit 4 – Cell Membrane & Transport

1. Unit 4 – Cell Membrane & Transport Identify the major structures within the cell membrane and their features. Describe how transport proteins allow certain molecules to pass through the plasma membrane. Compare and contrast diffusion and osmosis. Compare and contrast passive & facilitated diffusion. Compare and contrast passive and active transport.

2. Unit 4 – Cell Membrane & Transport Analyze how the cell uses endocytosis and exocytosis to obtain and release molecules. Analyze images illustrating hypotonic, hypertonic, and isotonic conditions. Predict the effect of a hypotonic, hypertonic, or isotonic solution on a cell Analyze lab/demonstration results relating to cellular transport. Print off the notes and highlight the vocabulary words from the objective sheet within the notes.

6. Obj. 1 – ID major membrane structures Color the following: protein, phospholipid, carbohydrate, cholesterol, hydrophobic & hydrophilic regions.

7. Obj. 1 – ID major membrane structures Identify each structure’s primary role: Carbohydrate- Cholesterol- Protein- Phospholipid-

8. Obj. 2 – Role of Transport Proteins Channel proteins are open to molecules moving through. Carrier proteins change shape to transport molecules.

9. Obj. 3 – Diffusion & Osmosis Diffusion is the passive movement of particles from high concentration to low concentration. Osmosis is the diffusion of water across a membrane (from [high] to [low]). A difference in concentration=concentration gradient.

10. Obj. 4 – Passive vs. Facilitated Diffusion Passive diffusion (diffusion) is the movement of molecules from [HIGH] to [LOW] through the membrane that does NOT require a protein. Facilitated diffusion still moves molecules from [HIGH] to [LOW], but it requires a protein for the molecules to move. They would not move without the protein.

11. Obj. 5 – Passive vs. Active Transport There are TWO differences that makes Active Transport different from passive transport (diffusion). Active transport moves molecules from [LOW] to [HIGH] Active transport requires energy (ATP)

12. Obj. 6 – Endocytosis & Exocytosis Endocytosis – Active transport of large molecules by absorbing them INTO the cell – creating a vesicle. Exocytosis – Active transport of large molecules OUT of a cell by fusing a vesicle with the membrane (exit). Watch this animation to see these processes in action: http://highered.mcgraw-hill.com/olc/dl/120068/bio02.swf You can also click on it from the Resource Links page.

13. Obj. 7 – Hypo-, Hyper-, & Isotonic Hypotonic solution is one that has a lower concentration of solute outside (=water into). Hypertonic solution is one that has a higher concentration of solute outside (=water out). Isotonic solution has equal net concentration of solute inside and outside (equal movement of water).

15. Obj. 8 – Predict effect in Hypo-, Hyper- Salt If this is a beaker of salt water and the circle represented a cell with a semi-permeable membrane, which direction would the water move? The opposite is what happens to plants on the side of the road in winter – plasmolysis.

16. Obj. 8 – Predict effect in Hypo-, Hyper- When a plant cell is placed in HYPERTONIC conditions the cell membrane detaches from the cell wall due to the shrinking cytoplasm (losing water).

17. Obj. 9 – Analyze Lab/Demo Results This space left blank for you to record Lab and Classroom Demonstration results.