Objectives for CH 6,7,11,12
CHAPTER 6
A TOUR OF THE CELL
Learning objectives:
How We Study Cells
1. Distinguish between magnification and resolution.
2. Describe the principles, advantages, and limitations of the light microscope, transmission electron microscope, and scanning electron microscope.
3. Explain why cell fractionation is a useful technique.
A Panoramic View of the Cell
4. Distinguish between prokaryotic and eukaryotic cells.
5. Explain why there are both upper and lower limits to cell size.
6. Explain the advantages of compartmentalization in eukaryotic cells.
The Nucleus and Ribosomes
7. Describe the structure and function of the nuclear envelope, including the role of the pore complex.
8. Briefly explain how the nucleus controls protein synthesis in the cytoplasm.
9. Explain the role of the nucleolus in protein synthesis.
10. Distinguish between free and bound ribosomes in terms of location and function.
The Endomembrane System
11. List the components of the endomembrane system, and describe the structure and function of each component.
12. Compare the structure and functions of smooth and rough ER.
13. Explain the significance of the cis and trans sides of the Golgi apparatus.
14. Describe the cisternal maturation model of Golgi function.
15. Describe three examples of intracellular digestion by lysosomes.
16. Name three different kinds of vacuoles, giving the function of each kind.
Mitochondria and Plastids
17. Briefly describe the energy conversions carried out by mitochondria and chloroplasts.
18. Describe the structure of a mitochondrion and explain the importance of compartmentalization in mitochondrial function.
19. Distinguish among amyloplasts, chromoplasts, and chloroplasts.
20. Identify the three functional compartments of a chloroplast. Explain the importance of compartmentalization in chloroplast function.
21. Describe the evidence that mitochondria and chloroplasts are semiautonomous organelles.
22. Explain the roles of peroxisomes in eukaryotic cells.
The Cytoskeleton
23. Describe the functions of the cytoskeleton.
24. Compare the structure, monomers, and functions of microtubules, microfilaments, and intermediate filaments.
25. Explain the structure and role of centrioles and basal bodies.
26. Explain how the ultrastructure of cilia and flagella relate to their functions.
Cell Surfaces and Junctions
27. Describe the basic structure of a plant cell wall. Distinguish between the primary cell wall, middle lamella, and secondary cell wall.
28. Describe the structure and roles of the extracellular matrix in animal cells.
29. Explain how the extracellular matrix may act to integrate changes inside and outside the cell.
30. Name the intercellular junctions found in plant and animal cells and list the function of each type of junction.
CHAPTER 7
MEMBRANE STUCTURE AND FUNCTION
Learning objectives
Membrane Structure
31. Explain the meaning of the statement that phospholipids and most other membrane constituents are amphipathic molecules.
32. Explain how the fluid mosaic model of membrane structure explains each experimental finding:
a. Actual membranes adhere more strongly to water than do artificial membranes composed only of phospholipids.
b. Membranes with different functions may differ in type and number of membrane proteins.
c. Membrane proteins are not very water-soluble.
d. EMs of freeze-fracture membrane preparations show protein particles interspersed in a smooth matrix.
33. Describe the fluidity of the components of a cell membrane and explain how membrane fluidity is influenced by temperature and membrane composition.
34. Explain how cholesterol resists changes in membrane fluidity as temperatures change.
35. Distinguish between peripheral and integral membrane proteins.
36. List six major functions of membrane proteins.
37. Explain the role of membrane carbohydrates in cell-cell recognition.
Traffic across Membranes
38. Explain how hydrophobic molecules cross cell membranes.
39. Distinguish between channel proteins and carrier proteins.
40. Explain how aquaporins facilitate the passage of water through membranes.
41. Define diffusion. Explain why diffusion is a passive and spontaneous process.
42. Explain why a concentration gradient of a substance across a membrane represents potential energy.
43. Distinguish between solutions that are hypertonic, hypotonic, and isotonic to cell contents.
44. Define osmosis and predict the direction of water movement based on differences in solute concentrations.
45. Describe how living cells with and without cell walls regulate water balance.
46. Explain how transport proteins facilitate diffusion.
47. Distinguish between osmosis, facilitated diffusion, and active transport.
48. Describe the two forces that combine to produce an electrochemical gradient.
49. Explain how an electrogenic pump creates voltage across a membrane. Name two electrogenic pumps.
50. Describe the process of cotransport.
51. Explain how large molecules are transported across a cell membrane.
52. Distinguish between exocytosis and receptor-mediated endocytosis.
CHAPTER 11
CELL COMMUNICATION
Learning objectives:
An Overview of Cell Signaling
1) Describe the basic signal-transduction pathway used for mating in yeast. Explain the evidence that these pathways evolved before the first multicellular organisms appeared on Earth.
2) Define ‘paracrine signaling’ and give an example.
3) Explain how plant and animal hormones travel to target cells.
4) List and briefly define the three stages of cell signaling.
Signal Reception and the Initiation of Transduction
5) Describe the nature of a ligand-receptor interaction and state how such interactions initiate a signal-transduction system.
6) State where signal receptors may be located in target cells.
7) Compare and contrast G-protein-linked receptors, tyrosine-kinase receptors, and ligand-gated ion channels.
Signal-Transduction Pathways
8) List two advantages of using a multistep pathway in the transduction stage of cell signaling.
9) Explain how an original signal molecule can produce a cellular response when it may not even enter the target cell.
10) Describe how phosphorylation propagates signal information.
11) Explain why a single cell may require hundreds of different protein kinases.
12) Explain how protein phosphatases turn off signal-transduction pathways.
13) Define the term ‘second messenger’. Briefly describe the role of these molecules in signaling pathways.
14) Describe how cyclic AMP is formed and how it propagates signal information in target cells.
15) Explain how the cholera bacterium causes the symptoms of cholera by disrupting G-protein signaling pathways.
16) Describe how the cytosolic concentration of Ca2+ can be altered and how the increased pool of Ca2+ is involved with signal transduction.
Cellular Responses to Signals
17) Describe how signal information is transduced into cellular responses in the cytoplasm and in the nucleus.
18) Describe how signal amplification is accomplished in target cells.
19) Explain why different types of cells may respond differently to the same signal molecule.
20) Explain how scaffolding proteins help to coordinate a cell’s response to incoming signals.
Apoptosis
21) Describe the roles of ced-3, ced-4, and ced-9 in apoptosis during embryonic development in Caenorhabditis elegans.
22) Describe the events that may trigger signals from within a cell to trigger apoptosis.
23) Describe the role of apoptosis in normal development and degenerative disease in vertebrates.
CHAPTER 12
THE CELL CYCLE
Learning objectives
The Key Roles of Cell Division
1. Explain how cell division functions in reproduction, growth, and repair.
2. Describe the structural organization of a prokaryotic and eukaryotic genome.
3. Describe the major events of eukaryotic cell division that enable the genome of one cell to be passed on to two daughter cells.
4. Describe how the chromosome number changes throughout the human life cycle.
The Mitotic Cell Cycle
5. List the phases of the cell cycle and describe the sequence of events that occurs during each phase.
6. List the phases of mitosis and describe the events characteristic of each phase.
7. Recognize the phases of mitosis from diagrams and micrographs.
8. Draw or describe the mitotic spindle, including centrosomes, kinetochore microtubules, nonkinetochore microtubules, asters, and centrioles (in animal cells).
9. Describe the changes in the mitotic spindle during each phase of mitosis.
10. Describe two mechanisms that explain how motor proteins associated with the kinetochore microtubules bring about the poleward movement of chromosomes.
11. Explain how nonkinetochore microtubules lengthen the cell during anaphase.
12. Compare cytokinesis in animals and plants.
13. Describe the process of binary fission in bacteria and explain how eukaryotic mitosis may have evolved from binary fission.
Regulation of the Cell Cycle
14. Describe the roles of checkpoints, cyclin, Cdks, and MPF in the cell cycle control system.
15. Describe the internal and external factors that influence the cell cycle control system.
16. Explain how the abnormal cell division of cancerous cells escapes normal cell cycle controls.
17. Distinguish between benign, malignant, and metastatic tumors.