4.4 Endomembrane System

4.4: The Endomembrane System Regulates Protein Traffic and Performs Metabolic Functions in the Cell 

You Must Know: 

• How internal membranes and organelles contribute to cell functions.

Key Terms: Endomembrane system, Vesicles, Endoplasmic Reticulum, Smooth ER, Rough ER, Glycoproteins, Transport Vesicles, Golgi Apparatus, Lysosome, Phagocytosis, Food Vacuoles, Contractile Vacuoles, Central Vacuoles

Bellwork: Watch and take notes on "Compartmentalization" Bozeman video.

IN CLASS READING of Concepts 4.4: Pages 82-87

1. Define the Key Terms above.
2. Decide which type of ER is continuous with the nuclear membrane.
3. Explain what is meant by the phrase, "The Rough ER compartmentalizes the cell."
4. Determine which feature of the rough ER shows that it is involved in making proteins.
5. List several functions of Smooth ER.
6. State the main component of cell membranes that are made in smooth ER.
7. Explain why the cells in the testes and ovaries are rich in smooth ER.
8. Predict what happens to the amount to smooth ER in the liver cells of an alcoholic or chronic drug user.
9. Determine where proteins produced by the rough ER are destined to go.
10. State the destination for proteins produced by free ribosomes.
11. Summarize the function of the Golgi Apparatus.
12. Create an analogy for the function of Lysosomes.
13. Explain what hydrolytic enzymes are.
14. Predict whether or not lysosomal enzymes will function in the near-neutral pH of the cytosol.
15. Research the role of the lysosomes in Apoptosis (programmed cell death).
16. Find a good video of a contractile vacuole and explain why unicellular, freshwater cells must have one of these structures.
17. Explain how the beauty of a flower is related to vacuoles.
18. Research an example of a plant toxin being stored in vacuoles.
19. Explain the role of a large, central vacuole in a plant cell maintaining turgor pressure (you'll have to find out what turgor pressure is first!).
20. Create a visual summary of the endomembrane system that shows what happens to proteins as they are produced (see figure 4.15).