Monday, October 21 (HS-LS1-3): Our work this week is to apply our learning of homeostasis to the cellular level. The primary focus of the lesson today was to provide students with the vocabulary to explain the concepts of osmosis and transport of water across the membrane via the membrane protein channel aquaporin.
To begin class, students will be introduced to the Egg Lab. Each student will receive a chicken egg, and they must measure and record the volume of their egg using water displacement. For this first day of the Egg Lab, students will then place the egg in a container with vinegar to begin the process of dissolving the shell.
Students will begin class by watching the Amoeba Sisters: Cell Transport video (below).
After the video, students will complete a worksheet that goes along with the Amoeba Sisters video.
Tuesday, October 22 (HS-LS1-3): To begin class, students will attend to their egg (Day 2). Their job today is simply to replace the vinegar without harming their egg. The fresh vinegar will continue to dissolve the egg shell over the next two days
Next, we will work through the Membrane Functions PowerPoint slide deck. Students should commit the vocabulary terms to memory. The aquaporin claymation video included in the slide deck is also provided below for easy access:
Wednesday, October 23 (HS-LS1-3): Next, we will finish working through the Slide Deck from yesterday and then students will apply their learning about osmosis by working through the Osmosis Gizmo on the Explore Learning website.
Any remaining time may be used to complete the Mitosis and Cancer BioInteractive from last week.
Keep Learning! Students who would like a more in-depth review of cell membranes and transport are encouraged to watch the Crash Course video below outside of class:
Thursday, October 24 (HS-LS1-3): For day 4 of the Egg Lab, students will work with their lab table groups to complete the following:
- Gently rinse each egg to remove any last parts of the shell.
- Gently dry each egg.
- Measure the volume of each egg separately using water displacement.
- Each student in the group should record the volume of each egg in their lab notebook. For example, a group of four students will each have four egg volume recordings in each student’s lab notebook.
- Rinse out the cup and dry it with a paper towel, and return the egg to the cup. Label the cup with the student’s name.
- Carefully cover the egg with one of the following:
- Vinegar (egg #1)
- Corn syrup (egg #2)
- Distilled water (egg #3)
- Bonus liquid (egg #4)
- Label the cup with the liquid used and then cover the cup with plastic.
- Record any additional observations about the egg during the class period.
- Return the cup to the fume hood for further observation tomorrow.
For the remainder of the class period, students should work hard to complete any missing biology assignments. We have an exam next Thursday, so students who are caught up on work should begin assembling a page of notes to use on the exam.
Friday, October 25 (HS-LS1-3): The egg lab concluded with students receiving the following instructions:
- Gently rinse and dry egg
- Measure and record the final volume using water displacement
- Discard the egg and cup
After discarding the eggs, cleaning up the lab station, and washing their hands (as they have been doing each day of the lab), students were tasked with working with their lab group to calculate the change in volume:
- from Day 1 (Monday, volume of eggs with shell) to Day 4 (Thursday, volume of eggs without shell)
- from Day 4 to Day 5 (volume of eggs after soaking overnight in various liquids)
A positive change means the egg gained volume. A negative change means the egg lost volume. Students reported out their data as a class (shown below), and then we discussed the movement of water across the membrane of eggs placed in various solutions (final picture below).