Name_______________________________________________ Biol 211 - Group Number________ ALE 4 - Page 1 of 10 Active Learning Exercise 4 Structure & Function of Cells and Membranes Reference: Chapters 6 & 7 (Biology by Campbell/Reece, 8th ed.) Cell Structure and Function (Reference: Chapter 6, Biology, 8th ed.) 1. Why is the study of cell structure and function important? 2. Explain what cell fractionation is and what it is used for. 3. a.) What are the major differences between prokaryotic and eukaryotic cells? Cite examples of each cell type. b.) Based on their cell structures, which cell type most likely evolved first: i.) prokaryotic cells or ii.) eukaryotic cells? Circle you choice and explain your reasoning.ALE 4 - Biology 211 (Revised Fall 2009) ALE 4 - Page 2 of 10 4. Why is it highly improbable that you will find a large predatory 40 kg cell on the slithering down the sidewalk? Hint: Discuss the selective advantage of cells being small and relate your response to how the surface area to volume ratio changes as cell size increases, and the efficiency of movement of substances (e.g. nutrients and waste products) by simple diffusion into, out of, and within cells. 5. Below is a diagram of a “typical” animal cell. After studying the structures in your textbook identify the labeled structures below without referring to your text or any other outside source. Name of structure a.) b.) c.) d.) e.) f.) g.) h.) i.) j.) k.) l.) m.) n.) o.) p.)ALE 4 - Biology 211 (Revised Fall 2009) ALE 4 - Page 3 of 10 6. Below is a diagram of a “typical” plant cell. After studying the structures in your textbook name the labeled structures below without referring to your text or any other outside source. Name of structure a.) b.) c.) d.) e.) f.) g.) h.) i.) j.) k.) l.) m.) n.) o.) p.) q.) r.) 7. Why is there really no such thing as a “typical” animal cell or “typical” plant cell? (Hint: structure determines function!) 8. List the major structural and resulting functional differences, between “typical” plant and animal cells?ALE 4 - Biology 211 (Revised Fall 2009) ALE 4 - Page 4 of 10 9. Complete the column entitled “Specific Functions”. Now cover this column with a sheet of paper. Can you now name the primary functions of the cell organelles listed in the table? If not, review the structures and their functions until you can. General Function(s) Organelle(s) Specific Functions Genetic control of the cell Nucleus - Chromosomes - Nucleolus - - Manufacture of macromolecules and perform metabolic functions - Ribosomes - Rough ER - Smooth ER - Golgi Apparatus - Lysosomes - Vacuoles Food vacuole: Contractile vacuole: Central vacuole (plants): - Peroxisomes Energy processing - Mitochondria - Chloroplasts (in some plants and protists) Support, movement, and communication between cells - Cytoskeleton - Cell wall (in archaea, plants, fungi, and some protists) - Intercellular junctions (Plasmodesmata in plants; Tight junctions, desmosomes, and gap junctions in animals)ALE 4 - Biology 211 (Revised Fall 2009) ALE 4 - Page 5 of 10 10. Lipase, a glycoprotein, is one of the many digestive enzymes found in a lysosome where it functions to digest fat molecules into fatty acids and glycerol. Trace the biosynthetic route the enzyme takes to its home in the lysosome: _________________ ER  transport vesicle  __________________  _________________  lysosome Membrane Structure and Function (Reference: Chapter 7, Biology, 8th ed.) 11. a.) Use a ruler to neatly label each of the following in the diagram of a plasma membrane below. Carbohydrate Cholesterol Cytoplasmic side Cytoskeleton Extracellular side Glycolipid Glycoprotein Hydrophilic head of phospholipid Hydrophilic regions of protein Hydrophobic regions of protein Hydrophobic tails of phospholipid Integral protein Peripheral protein Phospholipid bilayer b.) Describe the fluid mosaic model for plasma membranes. What makes the membrane fluid? What parts constitute the mosaic? What forces hold the phospholipid molecules together?ALE 4 - Biology 211 (Revised Fall 2009) ALE 4 - Page 6 of 10 12. Which of the following amino acids would most likely be present in the transmembrane domain of an integral membrane protein? a.) a charged amino acid like lysine b.) a polar amino acid like serine c.) a special amino acid like glycine or proline d.) a hydrophobic amino acid like valine e.) any of the above, with no preference 13. An animal cell membrane will be more fluid at room temperature if it contains... a.) more cholesterol. b.) longer chain fatty acids. c.) more cis-unsaturated and polyunsaturated fatty acids. d.) more unsaturated fatty acids. e.) any of the above 14. The carbohydrate molecules covalently linked to a protein (i.e. to form a glycoprotein) in the lumen of the rough ER may end up on the… a.) cytoplasmic face of the plasma membrane. b.) extracellular face of the plasma membrane. c.) cytoplasmic face of a secretory vesicle. d.) any of the above 15. How do hydrophilic substances (e.g. polar molecules and ions) enter and leave cells if they are unable to pass through the lipid bilayer of the plasma membrane? 16. Although ethanol, CH3CH2OH, is a polar molecule, it passes readily through the lipid bilayer of the plasma membrane of animal cells, but at high concentrations ethanol kills cells by dissolving the plasma membrane causing lysis of the cell. Explain these observations.ALE 4 - Biology 211 (Revised Fall 2009) ALE 4 - Page 7 of 10 17. Use the following terms to identify the kind of membrane function illustrated in the diagrams below and then briefly in your own words describe each function: Transport, Enzyme activity, Signal transduction, Cell-cell recognition, Intercellular joining, Attachment to the cytoskeleton & extracellular matrix a.) d.) b.) e.) c.) f.) 18. What is the major function of membrane glycoproteins and glycolipids? 19. a.) What is diffusion? b.) Why does diffusion occur?ALE 4 - Biology 211 (Revised Fall 2009) ALE 4 - Page 8 of 10 20. Complete the following table by indicating whether each substance is hydrophobic or hydrophilic, has a high or low permeability through the lipid bilayer of a plasma membrane, and then explain the reason behind the substance’s permeability. Substance