Cell Structure and Function types and transport
Cell Structure and Function: Cell Types and T r a n s p o r t Margaret Vorndam, M.S. Version 42-003700-01 Lab Report Assistant This document is not meant to be a substitute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment ’s questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate students’ writing of lab reports by providing this information in an editable file which can be sent to an instructor. Obser vations Data Table 1: Cell Structures Prokaryote Cell Structure Organism name: Flagella Eukaryotic Cell Structure Organism name: Pseudopodia Cell membrane Capsule or slime layer Nucleoid Nucleus Cytoplasm Plasma membrane Contractile vacuole Cytoplasm Ribosome Thylakoid vacuole Endospore Endospore Cell wall Food Data Table 2: Diffusion Rate Comparison Medium Semisolid (Gelatin) Liquid (Water) Beginning End Time, T1 Length of Time in hours Movement of color Rate of diffusion in Data Table 3: Diffusion through a Differentially Permeable Membrane At Beg inn ing At End of Exercise What are its contents? Dialysis Tubing Beaker Water What it its initial color? What is its final color? Benedict’ s te s t color NA What are its final contents? Exercise 1: Prokaryotes and Eukaryotes Differences in Cell Structure and Function Results 1. What differences are observed between the two cells that were drawn? 2. List the specific cell part that each cell type possesses to: Prokaryote Eukaryot e Store food? Reproduce? Questions A. With which cell type, prokaryote or eukaryote, are you most familiar? B. Which cell type would be most successful in extreme environments? Why? C. Because the Prokaryote bacteria are generally 3 µm or less in length, they may not exhibit specific structures under a compound light microscope. What type of microscope would be a better choice for viewing bacteria? D. Research amoebas online and give a few examples including where they are found and what energy source they use. E. Discuss whether cyanobacteria and amoebas are beneficial or detrimental to humans and to the environment in general. Exercise 2: Eukaryotes – Plant and Animal Cell Structure and Function Results 1. What differences are observed between the two cells that were drawn? 2. List the cell part that each cell type possesses to: Regulate water content? Produce energy to power cell Store food? Reproduce? Plant Vacuole Chloroplast Plastid or Vacuole Animal Vacuole Mitochondria Vacuole Questions A. With which cell type, plant or animal, are you most familiar? B. Which cell type would be most successful in extreme environments? Why? C. Outline the general differences between plant and animal cells in Table 1. Then outline the similarities. Table 1: Comparison of Structure and Function: Animal and Plant Cells Animal Cells Many lysosomes Can be phagocytic Contain cell membrane Contain centrioles Contain many vacuoles Round in shape Go through Photosynthesis Eukaryotic Contain nucleus Plant Cells Differences : Larger in size Contain chloroplasts Contain a cell wall made of cellulose Contain plastids Contain chlorophyll for Photosynthesis Contains single, large vacuole Similarities : Exercise 3: Transport of Materials through Cell Membranes – An Example of Passive Transport Questions A. Which medium exhibited the fastest rate of diffusion? B. What might be reasons to explain the differences in the rate of diffusion? C. Graph the two sets of results from Table 2 on the same graph using a computer spreadsheet program and include this graph in your report. Why is simultaneous graphing of the results useful here? What type of graph would best demonstrate rates of diffusion in gelatin versus liquid? Hint: The graph should show a continuity from To to T1 for both mediums. Discussion A. Were your two hypotheses supported or refuted? B. How might the rate of diffusion be increased? Decreased? C. How might this be tested? D. Why is this exercise be an example of passive transport? E. Why must the spread of the coloring in the gelatin be monitored? For example, why can it not just be left for 10 hours before the measurement is taken? F. What would be a graphic method to detect when the rate of diffusion in the gelatin was at maximum and was beginning to slow? G. Construct a table that compares your results to the average of your classmates’ results, if available. Indicate how many classmates’ results are represented in the average (N=?). Include it in your report. Are results similar? If not, what might explain the differences in outcomes? Exercise 4: Transport of Materials through Cell Membranes – An Example of Active Transport Questions A. What are the test substances? B. Why did a color change occur in the jar water? What does the color change indicate? C. Why did a color change occur in the dialysis bag? What does the color change indicate? D. What does the Benedict ’s reagent test detect? What does the test of the jar water indicate? E. What DID NOT diffuse across the dialysis bag membrane? Why? Discussion A. Was your hypothesis supported or refuted? B. How might the dialysis membrane tubing be similar to a plasma membrane? C. What type of transport mechanism does this exercise simulate? D. What can be concluded from this exercise? Laborator y Summar y What have you learned from doing this laboratory?