Transport LabTransport Lab
Molecular Biology – 2012Molecular Biology – 2012
Created by K. CrawleyCreated by K. Crawley
Transport LabTransport Lab
Question:Question:
How do we know transport occurs?How do we know transport occurs?
Objective:Objective:
To determine if molecules can betransported across a membrane.To determine if molecules can betransported across a membrane.
Transport LabTransport Lab
Hypothesis:Hypothesis:
What do you think will happen to thesolutions over time AND why?What do you think will happen to thesolutions 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 inwater containing iodine, then… because…If starch inside of a “cell” and placed inwater containing iodine, then… because…
Transport LabTransport 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 afterColor of Solution after
Elapsed Time (min)Elapsed Time (min)
InitialInitial
55
1010
1515
2020
2525
IodineSolutionIodineSolution
StarchSolutionStarchSolution
Procedure:Procedure:
Clean all glassware before using!Clean all glassware before using!
Put a small scoop of starch into a weighing boatPut a small scoop of starch into a weighing boat
Add the starch to your plastic bagAdd 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 cleanerSeal the bag closed using a pipe cleaner
twist it around the bagtwist it around the bag
Add ~125ml of water to a beakerAdd ~125ml of water to a beaker
Add ~10 drops of iodine to the beakerAdd ~10 drops of iodine to the beaker
Place the closed bag inside of the beaker with the tiedend above the waterPlace the closed bag inside of the beaker with the tiedend above the water
Write all observations in the data tableWrite all observations in the data table
Transport LabTransport Lab
Conclusion:Conclusion:
What conclusions can you make fromyour results?What conclusions can you make fromyour 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 ofyour plastic bag?What can you deduce about the permeability ofyour plastic bag?
Why can one substance go through the“membrane” and the other one can’t? Bespecific!Why can one substance go through the“membrane” and the other one can’t? Bespecific!
Transport LabTransport Lab
Conclusion, continued:Conclusion, continued:
Discuss errorsDiscuss errors
What are 3 ways you could improve thisexperiment if you were to do it again?What are 3 ways you could improve thisexperiment if you were to do it again?
Next steps & applicationNext 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 answeredin a future experiment, based on what you learnedor what sparked your interest from thisinvestigation?What question would you present to be answeredin a future experiment, based on what you learnedor what sparked your interest from thisinvestigation?