How do different liquids affect movement of materials across a membrane?
Initial Publication Date: August 25, 2009
Summary
In this biology lab students will investigate the movement of different materials across the cell membrane of a raw egg once the egg shell has been dissolved in vinegar. The initial part of this lab investigation will be conducted with the same procedure for all lab groups. Students will then be asked to develop an independent investigation in which they will choose a liquid that will "re-hydrate" the egg that has been "dehydrated" by the use of Karo syrup. Students will be asked to collect and analyze data into a conclusion to answer the question.
CollapseLearning Goals
Students will be able to:
- Observe movement of materials across a cell membrane and determine how and why it occurs
- Design an investigation to answer the question
- Develop a data table and collect data related to the question
- Analyze the data in a conclusion
Within this lab investigation students will be asked to use the following skills to aid in the investigation:
- observation
- model development
- questioning
- collecting data
- analyzing data
- writing
Concepts used is this lab investigation:
1. Students will review basic structure of a cell membrane.
2. Students will investigate why certain substances move across a cell membrane more efficiently than others.
Vocabulary terms: Osmosis, Hypotonic, Hypertonic, Isotonic, Selectively permeable membrane
- Observe movement of materials across a cell membrane and determine how and why it occurs
- Design an investigation to answer the question
- Develop a data table and collect data related to the question
- Analyze the data in a conclusion
Within this lab investigation students will be asked to use the following skills to aid in the investigation:
- observation
- model development
- questioning
- collecting data
- analyzing data
- writing
Concepts used is this lab investigation:
1. Students will review basic structure of a cell membrane.
2. Students will investigate why certain substances move across a cell membrane more efficiently than others.
Vocabulary terms: Osmosis, Hypotonic, Hypertonic, Isotonic, Selectively permeable membrane
Context for Use
This activity is designed for 10th grade general biology students. The students would have a limited background in these concepts at the time of this lab investigation. I have designed this activity to be conducted in lab groups of two people with a class size of 30 students. This lab will take place over the course of 5-6 days. However, it will not take an entire class period on each of those 5-6 days to conduct the lab. The first 3 days of the lab will take about 10 minutes each day while days 4-6 will take about 20-30 minutes each day. No special equipment is needed for this lab. I will be using raw eggs, plastic cups, plastic wrap, water, rubber bands and Karo syrup. Students will be asked to bring a liquid of their choice to school for the design portion of the experiment.
Student will have limited background knowledge before we begin this experiment. I do not intend to "front load" content before starting this lab. It is designed for them to explore movement through a membrane and we can discuss the specific concepts after the lab is finished. This lab will fit early in 2nd quarter of the school year in a unit the covers cell part structure and function. This lab could easily be adapted for other lab settings as well as manipulated to include other materials that simulate a cell membrane.
Student will have limited background knowledge before we begin this experiment. I do not intend to "front load" content before starting this lab. It is designed for them to explore movement through a membrane and we can discuss the specific concepts after the lab is finished. This lab will fit early in 2nd quarter of the school year in a unit the covers cell part structure and function. This lab could easily be adapted for other lab settings as well as manipulated to include other materials that simulate a cell membrane.
Description and Teaching Materials
This activity is designed to allow students to investigate how different materials affect movement of substances into and out of a cell (simulated by a raw egg). Students will be provided with a step by step procedure for the first three days of this 5-6 day lab. Initially students will place a raw egg in a plastic cup and cover it with vinegar. The egg will remain in the vinegar for 48 hours in order to dissolve the shell of the egg. After 48 hours the egg will be removed from the vinegar and rinsed. Students will measure the volume of vinegar remaining in the cup to the amount of vinegar they originally added to the cup. During day 3 of the lab students will place the egg back into the empty cup and cover the egg with Karo syrup. During day 4 of the lab they will remove the egg from the Karo syrup and measure the volume of Karo syrup remaining and compare it to the volume of syrup they initially placed over the egg on day 3. The second part of day 4 and into days 5 and 6 will allow students to design their own investigation related to egg re-hydration. Their task will be to design an investigation (including a question, procedure, predictions, data collection, and conclusions) using the egg that has spent 24 hours in Karo syrup as their starting point.
The following materials will be needed:
Plastic cup plastic wrap
Rubber band white vinegar
Karo syrup raw eggs, in shell
100 ml graduated cylinder liquid of student choice
Students would start day one of this lab on the first day of the chapter related to cell membrane structure and movement through a cell membrane. By the time the students reached day 3 of the lab they would have an understanding of cell membrane structure and function (but not necessarily the specifics of movement yet). I am hoping that the students will be able to discover how movement works through observing and collecting data after the egg is placed in Karo syrup and the liquid of their choice as well.
After the students have collect data and drawn conclusions related to their own investigations on day 5 and 6 of the lab. I have created several questions I would like them to answer and reflect upon.
1. What questions do you still have after this investigation? (Come up with at least 2!)
2. Compare your data with another group's data and record this in your notebook. What
similarities and differences exist between the two groups and why? Use a Venn Diagram to
show this in your notebook.
3. Create 3 diagrams to show what happened to the egg on Day 3, Day 4, and Day 5 of the lab. Use the terms hypotonic or hypotonic or isotonic as well as arrows to show how materials moved into or out of your egg. Record in your notebook.
4. Use the appropriate osmosis vocabulary to explain why fresh fruits and vegetables are sprinkled with distilled water at the grocery store. Make a labeled diagram as part of your answer. Record in your notebook.
5. Predict what would happen to a perch if it were placed in the Atlantic Ocean. Make a labeled diagram to support your answer. Record in your notebook.
6. Write a short paragraph in your notebook reflecting on this lab investigation and what you learned.
I also plan to have lab groups share informally their findings with the class.
I am unsure of the original source of this lab investigation that I have modified. I received the basic foundation of this lab from Jeanne Reed who is a biology instructor at Jefferson High School, Alexandria, Minnesota. Beyond her, I am unsure of this labs origin. How do different liquids affect movement of material through a membrane? (Microsoft Word 40kB Aug25 09)
The following materials will be needed:
Plastic cup plastic wrap
Rubber band white vinegar
Karo syrup raw eggs, in shell
100 ml graduated cylinder liquid of student choice
Students would start day one of this lab on the first day of the chapter related to cell membrane structure and movement through a cell membrane. By the time the students reached day 3 of the lab they would have an understanding of cell membrane structure and function (but not necessarily the specifics of movement yet). I am hoping that the students will be able to discover how movement works through observing and collecting data after the egg is placed in Karo syrup and the liquid of their choice as well.
After the students have collect data and drawn conclusions related to their own investigations on day 5 and 6 of the lab. I have created several questions I would like them to answer and reflect upon.
1. What questions do you still have after this investigation? (Come up with at least 2!)
2. Compare your data with another group's data and record this in your notebook. What
similarities and differences exist between the two groups and why? Use a Venn Diagram to
show this in your notebook.
3. Create 3 diagrams to show what happened to the egg on Day 3, Day 4, and Day 5 of the lab. Use the terms hypotonic or hypotonic or isotonic as well as arrows to show how materials moved into or out of your egg. Record in your notebook.
4. Use the appropriate osmosis vocabulary to explain why fresh fruits and vegetables are sprinkled with distilled water at the grocery store. Make a labeled diagram as part of your answer. Record in your notebook.
5. Predict what would happen to a perch if it were placed in the Atlantic Ocean. Make a labeled diagram to support your answer. Record in your notebook.
6. Write a short paragraph in your notebook reflecting on this lab investigation and what you learned.
I also plan to have lab groups share informally their findings with the class.
I am unsure of the original source of this lab investigation that I have modified. I received the basic foundation of this lab from Jeanne Reed who is a biology instructor at Jefferson High School, Alexandria, Minnesota. Beyond her, I am unsure of this labs origin. How do different liquids affect movement of material through a membrane? (Microsoft Word 40kB Aug25 09)
Teaching Notes and Tips
One of the biggest concerns I have about safety with this lab is the fact that students are handling raw eggs that are not refrigerated for up to six days. I am very careful to warn students about the potential hazards that could go along with that as well as stressing the importance of washing lab equipment, lab tables and hands with soap and water frequently. Students are required to wear goggles during this investigation and gloves could be used as well (although I have not required students to wear gloves).
I have run into student confusion related to use of a graduate cylinder during this lab. Some of my students are unsure of what to do if the volume they are trying to measure is greater than the volume of their graduated cylinder. To help ensure more accurate data, I have reviewed proper use of a graduated cylinder before starting this investigation.
I have changed this activity in a hopes to make it more inquiry based. Only minor modifications were made to day 1, 2, and 3 of the lab. I added a part that requires students to make a brief explanation based on observations they were making as well as a part where students were asked to make predictions about what they think will happen next. More significant changes have been made to day 4 and 5 allowing students freedom to design their own investigation and bring in their own materials. I am also asking students to create their own data table rather than me providing it for them. I also made some changes to the analysis part of the lab adding a section for data comparison with another group, further questions, and reflection on learning.
I have run into student confusion related to use of a graduate cylinder during this lab. Some of my students are unsure of what to do if the volume they are trying to measure is greater than the volume of their graduated cylinder. To help ensure more accurate data, I have reviewed proper use of a graduated cylinder before starting this investigation.
I have changed this activity in a hopes to make it more inquiry based. Only minor modifications were made to day 1, 2, and 3 of the lab. I added a part that requires students to make a brief explanation based on observations they were making as well as a part where students were asked to make predictions about what they think will happen next. More significant changes have been made to day 4 and 5 allowing students freedom to design their own investigation and bring in their own materials. I am also asking students to create their own data table rather than me providing it for them. I also made some changes to the analysis part of the lab adding a section for data comparison with another group, further questions, and reflection on learning.
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Assessment
Students will be required to record everything during this lab investigation in their notebook. I will collect the notebooks from the students and grade them using a rubric or checklist (I am not sure quite yet) that will be developed before they begin the lab investigation.
Standards
Life Science Grade 10 – 9.4.1.2.5
Benchmark – Compare and contrast passive transport (including osmosis and facilitated transport) with active transport such as endocytosis and exocytosis.
Benchmark – Compare and contrast passive transport (including osmosis and facilitated transport) with active transport such as endocytosis and exocytosis.