Week 3

Week 3: September 16-20

Monday, September 16 (LS1-2): After making and recording corn seed observations, students plant seeds in soil in preparation for the next phase of our experiment.

Next, students will discuss the analysis questions from last Friday’s assignment.  In The Breath of Life reading, students learned how the respiratory system of humans enables gas exchange, with the lungs inhaling oxygen and exhaling carbon dioxide.  The gas exchange occurs within the alveoli, thin-walled sacs inside the lungs.  The reading introduced the concept of feedback systems, focusing on the special nerve cells in the cardiovascular and nervous systems that can sense changes in pH.  As carbon dioxide builds up, the blood becomes more acidic, and the lungs are forced to exhale to rid the body of carbon dioxide which then brings the pH back to normal levels.

For the last few minutes of class, we made a list of some of the ingredients found in tacos, and then categorized those food items as carbohydrates, proteins, or fats.  We will dig into this work much more deeply tomorrow.

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Tuesday, September 17 (LS1-2):  After making and recording corn plant observations, students actively took notes and shared their understanding of biomolecules.  Glucose is a simple sugar and the key ingredient in cellular respiration, the process organisms use to generate vast amounts of ATP energy.  Sugars are one type of biomolecule.  Our work today was to learn about three major classes of biomolecules: proteins, fats (lipids), and sugars (carbohydrates).  We reviewed the monomers and polymers of each, and then students read pages 328-332 in our textbook and completed the associated worksheet.  The assigned reading is titled Food: Our Body’s Source of Energy and Structural Materials.  Now that students understand the link between photosynthesis (chemical potential energy stored in glucose), cellular respiration (glucose metabolized to transfer the energy in glucose to ATP), and the larger connection with the respiratory and cardiovascular systems, it is time to learn more about how the digestive system makes use of the variety of foods available to us.  It is time to think beyond glucose.

Notes from class:

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Wednesday, September 18 (LS1-2): After making and recording corn plant observations, we reviewed the reading from yesterday and focused in on an important group of enzymes responsible for digestion in the human digestive system.  For the remainder of class, students worked with a partner on the Digestive System Gizmo activity packet.

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Thursday, September 19 (LS1-2): After making and recording corn plant observations for the final time, students will work with a partner to complete the Digestive System Gizmo activity packet.

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Friday, September 20: Students had the entire short Friday class period to work on the Digestive System Gizmo activity packet.  Students were instructed to complete, at a minimum, through Activity B as homework before class on Monday.

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Keep Learning!

Watch The Digestive System video by Mr. Anderson at Bozeman Science to learn more about this important area of study!

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Setting up the Garden

Students established their Baggie Garden experiments today, setting up their experiment bags and one or more experimental control bags.  We began class with a brief overview of the day, and then students worked in groups to write a detailed experimental procedure.  Once their procedure was reviewed and teacher-approved, the students assembled their baggie gardens, using the resources available to test their hypotheses.

For groups testing temperature as their manipulated variable:

• Freezer -10C
• Refrigerator 9C
• Room 23C
• Warm box 30C

Tomorrow we will make our first experimental observations and then discuss how to organize how to collect and organize data relevant to each group’s research question.

Testable Experimental Variables

To extend our study of ecology, we will invest the next two weeks reviewing the scientific process through the lens of plant biology.  Our work today will involve identifying testable experimental variables associated with plant seed germination. Tomorrow, students will establish baggie gardens in order to test whether their selected variable impacts seed germination and/or seedling growth.  Our collective data will enable us to make detailed scientific observations and conclusions about factors affecting seed germination, seedling growth, and photosynthesis.  Along the way, students will practice the art of inquiry by:

• identifying variables (manipulated, responding, and controlled)
• writing hypothesis statements (using the if…then…because… format)
• writing a detailed experimental procedure (incorporating the concepts of validity, reliability, repeated trials, and experimental control conditions)
• recording, organizing, and analyzing detailed observations
• writing a conclusion statement

Students will be expected to produce a typed lab report which includes a data table and a graph of the data.

Notes from class today:

Unit 2 Review

We packed a lot into our short Friday class period today, starting off with a return to the potato catalase lab packet.  We worked through pages 4-6 and students were directed to find the results from all of the classes on yesterday’s lesson post.  Students also received a copy of the Potato Catalase Lab Report Checklist and learned that they may work with a partner to complete the report and the due date is December 1.  Students were told that they can turn the report early to receive feedback which can be used to revise and improve their report by the due date.

For the last part of class, we reviewed Unit 2 content, with students encouraged to review the process of a slice of pizza or a cheeseburger being digested.  Students should practice writing an explanation which breaks down the parts of the food into biomolecules, explaining how those molecules are digested (anatomy of the digestion system and enzymes involved), and then explaining how the biomolecules are absorbed into the body and reassembled (biosynthesis) to form new biomolecules the body needs to live.

Potato Catalase Lab

For the lab today, students were instructed to record the steps of the procedure in their lab notebooks.  Steps were provided orally to emphasize the absolute importance of active listening (and not talking) while instruction is being delivered.  Students conducted the lab working in groups and recorded data in a class data table on the white board.  Results from all three classes are provided below:

Period 1	Raw	Boiled	Frozen	Vinegar	Ammonia
% O2 start	17.06	17.81	17.58	17.65	18.21
% O2 final	16.10	17.80	18.96	18.49	18.14
Time (sec)	379	213	900	321	160
Mass of potato (g)	3.8	5.1	3.5	3.8	3.8
Period 4	Raw	Boiled	Frozen	Vinegar	Ammonia	Raw
% O2 start	17.66	16.60	17.65	16.58	17.40	17.60
% O2 final	19.47	16.65	18.60	16.41	17.44	17.58
Time (sec)	600	226	417	247	285	300
Mass of potato (g)	5.5	6.5	5.9	5.6	6.9	8.1
Period 6	Raw	Boiled	Frozen	Vinegar	Ammonia
% O2 start	17.70	16.81	16.81	17.17	17.55
% O2 final	17.52	16.74	17.15	17.88	17.59
Time (sec)	300	300	300	300	300
Mass of potato (g)	8.1	3.1	6.3	7.9	4.9
Mr. Swart	Raw	Raw	Raw
% O2 start	17.34	17.04	17.88
% O2 final	18.12	17.62	18.12
Time (sec)	300	300	300
Mass of potato (g)	6.6	6.9	7.9

Potato Catalase Pre-Lab

Class began with a brief review of the Amoeba Sisters enzyme worksheet from yesterday and then we transitioned to preparing for the potato catalase lab.  After turning in the enzyme worksheet, students picked up a catalase lab packet.  We discussed the function of catalase and then students had the remainder of class to complete the first three pages of the packet.  Students were told multiple times that the first three pages of the packet must be completed before they can participate in the lab tomorrow.  Students who did not finish the first three pages of the packet in class were instructed to complete the work as homework.  The following notes were shared to help students better understand how the lab would be conducted:

Enzymes

We began class with a vocabulary review from yesterday.  Students completed Activity D problem #3 where they matched 11 digestion related vocabulary words with the correct definitions.  Next, we reviewed the enzymes from yesterday’s lesson to reinforce vocabulary and to review where in the body the enzymes work and which biomolecules they act on.  Notes from the white board are shown below:

For today’s lesson, we furthered our study of enzymes by watching the Amoeba Sisters video below:

After the video, students had time to work on the video worksheet in class and were instructed to finish it as homework.

Digestion

We continued our study of enzymes and digestion by focusing specifically on the process of digestion today.  Students all received a handout with an image of the digestive system, and then we labeled the parts and took notes on the process of digestion while watching the video below:

Additional notes from the whiteboard are shown below:

Biomolecules

Class began with the following entry task:

Use the Item Bank (H20, CO2, ATP, O2, C6H12O6):

1. Which are inputs of cellular respiration?
2. Which are outputs?
3. Write the equation for cellular respiration

The entry task launched our brief review of cellular respiration, photosynthesis, and chemical potential energy stored in glucose and transferred to ATP.

After taking notes, the discussion transitioned to a recognition that while humans can eat glucose directly by consuming plants, humans can also obtain energy by eating other animals that eat plants.  For example, when we eat beef, we are ingesting protein and fat (lipids) produced by a cow that ate grass.  That led us to the Biological Molecules Crash Course video (below) and the associated worksheet.  Each student was assigned one question from the handout to answer, and then students combined answers in a class share-out at the end of class.  A completed copy of the worksheet is also provided below.

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November 8 – Updated

Our study of biomolecules continued with students working in groups of three to read about carbohydrates, lipids, and fats.  Each student read one section, and then all three shared what they learned with the other students in the group so that each student was able to complete one worksheet.  At the end of class, we re-grouped and created the summary table shown below:

Food – Our Body’s Source of Energy

At this point in our study of enzymes and digestion, students have learned how plants capture the energy in sunlight and store it as chemical potential energy in glucose molecules.  Animals (and plants!) metabolize glucose using cellular respiration, transferring the chemical potential energy from glucose to ATP (adenosine triphosphate), the energy currency of cells.  Photosynthesis takes place in chloroplasts, while cellular respiration occurs in mitochondria.

In The Breath of Life reading, students learned how the respiratory system of humans enables gas exchange, with the lungs inhaling oxygen and exhaling carbon dioxide.  The gas exchange occurs within the alveoli, thin-walled sacs inside the lungs.  The reading introduced the concept of feedback systems, focusing on the special nerve cells in the cardiovascular and nervous systems that can sense changes in pH.  As carbon dioxide builds up, the blood becomes more acidic, and the lungs are forced to exhale to rid the body of carbon dioxide which then brings the pH back to normal levels.

For today’s lesson, we once again turned to our textbook and students were instructed to read pages 328-332 and complete the associated worksheet.  The assigned reading was titled Food: Our Body’s Source of Energy and Structural Materials.  Now that students understand the link between photosynthesis (chemical potential energy stored in glucose), cellular respiration (glucose metabolized to transfer the energy in glucose to ATP), and the larger connection with the respiratory and cardiovascular systems, it is time to learn more about how the digestive system makes use of the variety of foods available to us.  It is time to think beyond glucose.