Eukaryotes, Prokaryotes, and Viruses: Structure and Function Student Name Vicki Gonzales Date 2/28/2022 1. Prelab Questions 1. There are three panels in the figure below (as labeled). Each panel represents two compartments separated by a semi-permeable membrane. Small solid circles represent water and larger hashed circles represent a solute. In each panel label each side (“Side A” and “Side B”) as either hypertonic, hypotonic, or isotonic. After doing this, illustrate (with an arrow) or state which direction water will move (left-to-right, right-to-left, or neither). Panel 1 would move from side a to b because the solutes on side b are higher, side a is hypertonic while side b is hypotonic. Panel 2 would not move from either direction because each side has the same amount of solute. Both sides a and b are hypertonic which would make them isotonic. Panel 3 would move from side b to a because side a has more solutes than side b. Side a is hypotonic and side b is hypotonic. →→→→→→→→ neither ←←←←←←←←←← 2. IKI (also called iodine-potassium iodide) is a reagent that turns black in the presence of starch. Benedict’s regent is a reagent that turns clear blue in the presence of glucose. As a student in BIO111 you are asked to set up an experiment that has a beaker that has been partitioned by a semi-permeable membrane and you have placed a solution contain 20% glucose on one side of the beaker while on the other side you have placed a solution containing 20% starch. See figure below. 1 © 2016 Carolina Biological Supply Company Considering this setup answer the following questions: a. After two hours you remove a sample from side A and B and test them for starch and glucose using the IKI solution and benedict’s reagent. Predict, or hypothesize, what you will find for both side A and side B given this scenario. Why did you make that prediction? The sample would test b. After making your prediction you carry out the test and find that glucose is found on both sides A and B. However, starch is found only on side A. Why do you think this is the case? Answer this question by discussing the molecular difference between glucose and starch. c. How does the scenario described in b. compare to a biological membrane? 3. In Activity 1 of this lab we will be investigating the impact that the surface area-to-volume ratio has on the rate of diffusion. Please read the directions for Activity 1 in the investigative manual. After doing so fill in your purpose and hypothesis statements found under the Activity 1 2 © 2016 Carolina Biological Supply Company heading. After completing the lab come back to this section and fill out your evidence/claims and reflection statement. Activity 1 Instructions: 1. Open the investigative manual. Locate all the needed materials supplied in the kit and those you will need to supply yourself. 2. Lay them out in your work area. 3. Read through the entire set of instructions found in the investigative manual for the activity to avoid making mistakes when you go to execute the experiment. 4. Once you have read through the instructions go back to step 1 and begin executing the experiment. 5. Please answer the questions below and/or append appropriate representations of data (photos, graphs, etc). REMEMBER don’t clean up until you have taken the appropriate photos of your experiment as described below. Purpose statement: (This should be the question the experiment is attempting to address. It should be written as a question.)Do molecules pass more efficiently in and out of a cell with a larger surface-to-volume ratio than a cell with a small surface -to-volume ratio? Hypothesis statement: (This should be an “if/then” testable prediction that addresses the question/purpose of the lab.)If the surface-to-volume ratio is larger than that of a smaller cell then the iodine shouldn't penetrate as far into the potato as the potato with a smaller surface-to-volume ratio. Evidence/Claim statement: (This should be a statement regarding whether your hypothesis was supported or refuted and what data/evidence allows you to make this claim.)Evidence from the experiment shows that the surface area-to-volume does play a role in how much the iodine permeates the potato. In the 2.50cm potato, the surface area-to-volume was .8 while the .50cm potato had a surface area-to-volume of 12.(carolina, 2016) Reflection statement: (This should be a statement of what you learned, how your understanding changed, if you have new questions, and what connections can 3 © 2016 Carolina Biological Supply Company you make between the lab and the content in the book and other assignments.)What i learned is the cell structure has everything to do with how the cell allows things to pass through its membrane. that size and structure does effect how a cell functions . 4 © 2016 Carolina Biological Supply Company Photo 1 – Activity 1 5 © 2016 Carolina Biological Supply Company Take a picture and insert the image(s) of your potato blocks after step 5 of the “Procedure” section in activity 1 of the investigative manual: 6 © 2016 Carolina Biological Supply Company 7 © 2016 Carolina Biological Supply Company Data Table 1A Length (l) (cm) Width (w) (cm) Height (h) (cm) Size of cross section slice (h x w) (cm) Distance traveled by IKI from potato edge (cm) Area of white region (l × w) (cm2) 2.50 2.50 2.50 6.25 cm .5 cm 4 cm ^2 2.00 2.00 1.00 2 cm .8 cm 3cm^2 1.50 1.50 1.50 2.25 cm 1.25 cm 2.56cm^2 1.00 1.00 1.00 1 cm .9 cm 2 cm^2 2.00 0.50 0.50 .25 cm .45 cm 1.56cn^2 0.50 0.50 0.50 .25 cm .4 cm 1 cm^2 8 © 2016 Carolina Biological Supply Company Data Table 1B Lengt h (l) Widt h (w) Heigh t (h) Surface area of block (l x w x 2) + (w x h*4) (cm2) 2.50 2.50 2.50 37.5cm ^2 2.00 2.00 1.00 16cm^ 2 1.50 1.50 1.50 13.5cm ^2 1.00 1.00 1.00 6cm^2 0.50 0.50 2.00 0.50 0.50 0.50 1.5cm^ 2 1.5cm^ 2 Volum e (l x w x h) (cm3) 15.63 cm^ 3 4cm ^3 3.375 cm^ 3 1cm ^3 15c m^3 .125c m^3 Surface area-to-volu me ratio (Surface area of block/volum e) .8 .5 4 6 5 12 Surfac e area of slice (w x h) (cm2) 6.25 cm^ 2 2cm ^21. 2.25 ^2 1cm ^2 .25c m^2 .25c m^2 Surface area of white section (cm2) Surface area of black section (cm2) Percent of potato block saturated with IKI: (Surface area of black section/surfac e area of slice)*100 4cm^ 2 2cm^ 2 1.5cm 1.8cm ^2 .2cm ^2 1,3 cm .75^2 1.5^2 1.5 .2cm^2 .05cm ^2 .05cm ^2 .8cm ^2 2cm^ 2 2cm^ 2 1.4 1.09 1.09 1. Go back to the prelab and fill in the “Evidence/Claim” and “Reflection” statement for this lab activity. 2. Make a line graph of the “percent of potato block saturated with IKI” (y-axis) vs. “Surface area-to-volume ratio” (x-axis) and answer the questions below. 9 © 2016 Carolina Biological Supply Company a. Insert graph here (make sure your graph has a title, labeled axis, and a legend): b. What does this graph, and the results of this experiment, tell us about how the rate of diffusion changes with changing surface-area-to-volume ratio? This shows that the surface area-to-volume is larger than that of the full penetration on a smaller object. whereas on a larger potato, the surface area is smaller but the penetration is larger. This is because cells are able to pass through faster on a larger object than one smaller. (carolina,2016) 10 © 2016 Carolina Biological Supply Company c. Finally, what can we conclude from these results regarding why biological cells are small rather than large? The conclusion is that the cells are smaller because a smaller potato is over taken by iodine faster due to the cell needing more oxygen and nutrients to be able to do its job while the larger potato is able to do the process faster because it is able to hold more oxygen and nutrients at the same time as functioning 11 © 2016 Carolina Biological Supply Company Activity 2 12 © 2016 Carolina Biological Supply Company 1. 13 © 2016 Carolina Biological Supply Company 14 © 2016 Carolina Biological Supply Company 1 1 15 © 2016 Carolina Biological Supply Company Photo 1 – Activity Take a picture and insert the image(s) of your dialysis tubes after step 14 of the “Preparing the Dialysis Tubing” section in activity 2 of the investigative manu 16 © 2016 Carolina Biological Supply Company 17 © 2016 Carolina Biological Supply Company Data Table 2 Sample data shown. Solution in cup Initial volume (Vi) (mL) Final volume (Vf) (mL) Change in volume (Vf-Vi) (mL) 20% sucrose 20% sucrose 90 mL 90 mL 0mL 0% isotonic B 40% sucrose 20% sucrose 90 mL 92 mL 2 mL 2.22% increase hypotonic C 20% sucrose 40% sucrose 90 mL 89 mL 1 mL 1.11% decrease hypertonic Treatment Solution in dialysis tubing A Percent change 2mLin volume (Vf-Vi)/Vi (mL) The solution inside the tubing was hypotonic, isotonic or hypertonic? 1. Explain what the change in volume of the dialysis tube indicated. Describe what happened when the volume increased and when the volume decreased. During the experiment, the volume of the granulated cylinder changed or stayed because of the transfer of solutes. In the solution of (20% sucrose, 20% sucrose) the volume stayed the same because the dialysis tubing neither released the solution nor gained water making it isotonic. In the (40% sucrose, 20% sucrose) the dialysis tubing gained water from the granulated cylinder causing the volume to increase making it hypotonic. finally, the (20% sucrose, 40% sucrose) released its solution from the dialysis tubing into the surrounding water of the granulated cylinder causing the water to decrease making it hypertonic.(Carolina manual, 2016) 2. Are the results of your experiment consistent with what you would have expected to happen? Why or why not? The results of both a and b are what was expected however sample c was thought to be heavier than both samples a and b. I figured with the solution of 40% being on the outside it would transfer into the dialysis tubing and be heavier in weight. 18 © 2016 Carolina Biological Supply Company 19 © 2016 Carolina Biological Supply Company Activity 3 Instructions: 1. Open the investigative manual. Locate all the needed materials supplied in the kit and those you will need to supply yourself. 2. Lay them out in your work area. 3. Read through the entire set of instructions found in the investigative manual for the activity to avoid making mistakes when you go to execute the experiment. 4. Once you have read through the instructions go back to step 1 and begin executing the experiment. 5. Please answer the questions below and/or append appropriate representations of data (photos, graphs, etc). REMEMBER don’t clean up until you have taken the appropriate photos of your experiment as described below. Photo 1 – Activity 3 Insert the photo or scan of your prokaryotic cell drawing from Activity 3. The following should be indicated in this photo: ● cell membrane type ● circular DNA ● ribosomes ● flagellum (if applicable) ● Identification of the cell tracing your steps through the Dichotomous key 20 © 2016 Carolina Biological Supply Company o For example: 1a 🡪 2a 🡪 3a (Staphylococcus aureus) 21 © 2016 Carolina Biological Supply Company 22 © 2016 Carolina Biological Supply Company 23 © 2016 Carolina Biological Supply Company Photo 2 – Activity 3 Insert the photo or scan of your eukaryotic cell drawing from Activity 3. The following should be indicated in this photo: ● double-stranded DNA inside a nuclear membrane ● ribosomes ● mitochondria ● endoplasmic reticulum ● lysosomes ● ● ● ● ● 24 Golgi apparatus vesicles optional internal organelles means of locomotion if applicable Identification of the cell tracing your steps through the Dichotomous key o For example: 1a 🡪 6a (plasmodial slime mold) © 2016 Carolina Biological Supply Company 25 © 2016 Carolina Biological Supply Company 26 © 2016 Carolina Biological Supply Company Photo 3 – Activity 3 Insert the photo or scan of your virus drawing from Activity 3. The following should be indicated in this photo: ● capsid shape ● DNA or RNA, if it is single stranded or double stranded, and the replication direction ● Identification of the cell tracing your steps through the Dichotomous key o For example: 1a 🡪 2b 🡪 9a 🡪 10b (unidentifed) 27 © 2016 Carolina Biological Supply Company 28 © 2016 Carolina Biological Supply Company sources: Carolina Biological Company. (2016). Cell structure and function: eukaryotes, prokaryotes and viruses. investigation manual and lab 29 © 2016 Carolina Biological Supply Company