Study Guide 7
Last revised: Monday, August 27, 2001

Topic: Eukaryotic Cell Structure and Function

Chapter 7.

1. Terms. Be able to recognize and correctly apply the following terms. Note: other terms not listed here are found throughout the following questions.

   Chromatin	Chromosome	Nucleolus	Ribosome
   Lysosome	Phagocytosis	Mitochondria	Chloroplast

   
   
2. Biological objects are measured with the metric system. If your metric skills are rusty, use the following activity as a review: (activate your subscription to "The Biology Place" first): A Review of the Metric System
3. Study Fig. 7.1. How big are the smallest cells? How big are most bacteria? How big are most plant and animal cells? Can cells be seen with the unaided human eye? Can viruses be seen with the light microscope? What are the smallest biological objects that can bee seen with the light microscope?
4. What is meant by cell "fractionation"? What laboratory instruments are typically used to fractionate cells?
5. What is the surface-to-volume ratio of a cubic cell 1 μm in length? 10 μm in length? Based on this analysis, how would you predict that cells of these two sizes would differ?
6. What is a "plasma membrane"? Where is it found? What does it do? Could a cell survive without one?
7. What is resolving power? What are the resolving powers of the following optical instruments: (a) human eye, (b) light microscope, (c) electron microscope?
8. The following list jumbles biological objects without reference to size. Sort this list into a sequence from smallest to largest:
   Nucleus, Protein molecule, Plant cell, Glucose molecule, Ribosome, Mitochondrion
9. How could you distinguish a transmission electron micrograph from a scanning electron micrograph? (Note: a “micrograph” is a picture taken through a microscope).
10. Distinguish prokaryotes from eukaryotes. Which of the following are found in a bacterial cell? In a plant cell? In an animal cell?
    nucleus:
    70S ribosome:
    80S ribosome:
    DNA:
    cytoplasmic membrane:
    cell wall:
11. Cell sizes are typically measured in micrometers (μm). If you were shown an electron micrograph of a bacterium, how big would you expect it to be (ball park estimate)? How big might a “typical” animal cell (there ain’t no such thing, but indulge the fantasy momentarily) be?
12. Why are rER, sER, lysosomes, plasma membrane, and Golgi bodies all considered parts of the endomembrane system, but mitochondria are not?
13. What is a lysosome? What is phagocytosis? How are lysosomes involved in phagocytosis?
14. What is the signal hypothesis? What does it explain?
15. Which of the following structures is bounded by a double membrane system?
    mitochondrion
    rough ER
    smooth ER
    Golgi body
    nucleus
    cytoplasm
16. What is the difference between a vacuole and a vesicle? How does the role of vacuoles differ in animal (especially single-celled protists) and plant cells?
17. In what ways are mitochondria and chloroplasts similar? In what ways are they different?
18. What is a peroxisome?
19. How could you distinguish a microtubule from a microfilament? Describe common functions of each.
20. Scientists have been able to identify the organization of cytoskeletal fibers much more easily using light microscope techniques rather than electron microscope techniques, even though the individual fibers are too small to be seen by light microscopes. What special technique has made light microscopy so useful in this case?
21. Identify three cell structures in which you could find microtubules.
22. Identify a specific activity in which the proteins kinesin and dynein are involved. Note that these are important as "motor molecules". See Fig. 7.21 and 7.25 especially.
23. Be able to identify major functions for each of the cell components listed in the Key List below (flashcards work well for this sort of exercise).
24. Match descriptions on the left with items in the Key List. (Note: Key List items may be used more than once, or not at all.)

Site of ribosome assembly Site of RNA synthesis Site of synthesis for enzymes that will be found inside lysosomes Filaments found in cilia and flagella Boundary between cell and its environment Site of synthesis of proteins for export from cell Site of synthesis of membrane lipids Structures in eukaryotic cells that contain ribosomes (more than one answer) Structure(s) that keeps chromosomes out of cytoplasm Region of cell that contains hydrolytic enzymes capable of breaking down polymers Compartments where most cell energy is produced (more than one answer)

KEY LIST Nucleus Nucleolus Nuclear membrane rER sER Golgi complex cytoplasm lysosome plasma membrane mitochondrion chloroplast vacuole microtubule microfilament (actin) ribosome peroxisome

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