Transport Lab Molecular Biology – 2012 Created by K. Crawley

Transport Lab Question: Question: How do we know transport occurs? How do we know transport occurs? Objective: Objective: To determine if molecules can be transported across a membrane. To determine if molecules can be transported across a membrane.

Transport Lab Hypothesis: Hypothesis: What do you think will happen to the solutions over time AND why? What do you think will happen to the solutions over time AND why? Will iodine go inside the bag? Will iodine go inside the bag? Will starch leave the bag? Will starch leave the bag? If starch inside of a “cell” and placed in water containing iodine, then… because… If starch inside of a “cell” and placed in water containing iodine, then… because…

Transport Lab Data Table: Data Table: Draw the following data table on your lab paper: Draw the following data table on your lab paper: Color of Solution after Elapsed Time (min) Initial Iodine Solution Starch Solution

Procedure: Procedure: Clean all glassware before using! Clean all glassware before using! Put a small scoop of starch into a weighing boat Put a small scoop of starch into a weighing boat Add the starch to your plastic bag Add the starch to your plastic bag Add ~100ml of water to the bag (use your beaker) Add ~100ml of water to the bag (use your beaker) Seal the bag closed using a pipe cleaner Seal the bag closed using a pipe cleaner twist it around the bag twist it around the bag Add ~125ml of water to a beaker Add ~125ml of water to a beaker Add ~10 drops of iodine to the beaker Add ~10 drops of iodine to the beaker Place the closed bag inside of the beaker with the tied end above the water Place the closed bag inside of the beaker with the tied end above the water Write all observations in the data table Write all observations in the data table

Transport Lab Conclusion: What conclusions can you make from your results? What conclusions can you make from your results? Did iodine enter the bag? How do you know? Did iodine enter the bag? How do you know? Did starch leave the bag? How do you know? Did starch leave the bag? How do you know? What can you deduce about the permeability of your plastic bag? What can you deduce about the permeability of your plastic bag? Why can one substance go through the “membrane” and the other one can’t? Be specific! Why can one substance go through the “membrane” and the other one can’t? Be specific!

Transport Lab Conclusion, continued: Discuss errors Discuss errors What are 3 ways you could improve this experiment if you were to do it again? What are 3 ways you could improve this experiment if you were to do it again? Next steps & application Next steps & application How can these findings be applied to real life? How can these findings be applied to real life? What question would you present to be answered in a future experiment, based on what you learned or what sparked your interest from this investigation? What question would you present to be answered in a future experiment, based on what you learned or what sparked your interest from this investigation?