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Slide A

Last time, we conducted a series of investigations to determine if chemical reactions happen in the mouth. We:

Made observations about eating a cracker.
Analyzed data from eating a graham cracker.
Conducted an investigation to determine if chemical reactions occur in the mouth.

What evidence did we use to support our claims to answer the question, “Do chemical reactions occur in the mouth?”

Turn and Talk

Be ready to share these ideas in a few minutes.

Look back at what we figured out about chemical reactions in the mouth. Present slide A and remind students that last time we were working on figuring out whether chemical reactions happen in the mouth. Remind students that we decided to take a deeper dive into the digestive system of a healthy person because we think that it might help us figure out what is different about M’Kenna’s digestive system. Prompt students to turn and talk with a partner about the question, “What evidence did we use to support our claims about the question, ‘Do chemical reactions occur in the mouth?’” Provide students several minutes to gather their ideas with a partner, then prompt students to share their ideas with the class in a Building Understandings Discussion.

Purpose of this discussion: This discussion serves as a way to pull together the progress that students made in Lesson 5. In this discussion, students work to represent the idea that chemical reactions occur in the mouth, which helps to explain why some food molecules increase and some decrease.

Listen for these ideas:

Chemical reactions occur in the mouth.
An enzyme called amylase helps break some types of complex carbohydrates down into glucose molecules.
There is an increase in glucose because some types of complex carbohydrates are being broken down into glucose.

Suggested prompts…..Sample student responses

What did we figure our last class? Do chemical reactions occur in the mouth? … Yes, we found out that big food molecules, like certain types of complex carbohydrates, are being broken down into smaller food molecules, like glucose. They are not just bigger chunks of complex carbohydrates being turned into little chunks of the same thing. The smaller food molecules really are different molecules with different properties.
What evidence do we have to support our claims?... When we made observations about eating a cracker, we noticed that our teeth seemed to break apart the cracker and that spit mixes with the cracker. When we examined the data from a healthy person eating a graham cracker, we noticed that the amount of other complex carbohydrates in the mouth decreases and the amount of glucose increases. We read an article that provided us with evidence that a special enzyme called amylase can break down substances in the mouth. We conducted an investigation to determine if amylase breaks some types of complex carbohydrates down into glucose, and we discovered that it does!

Add the word “digestion” to the word wall. Say, When our bodies take big food molecules and break them down into smaller food molecules through chemical reactions, we call that “Digestion = a chemical reaction to break down food.”

Say, It sounds like we made a really important discovery about what is happening in the mouth! Let’s capture this on our Progress Trackers.

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Add to Our Progress Trackers

Slide B

Work with a partner to construct a 30-second argument using evidence and scientific reasoning that can support how we should add to our Progress Trackers and revise our model for what happens to food as it passes through the digestive system. You will spend two minutes with your partner finding evidence in your science notebooks and creating an argument to share with the whole group.

After arguing from evidence with your class, add to your Progress Tracker.

Progress Tracker

Question

What I figured out

Why do large food molecules, like complex carbohydrates, seem to disappear in the digestive system?

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Slide C

Discuss the following questions as a class:

Do you think that all of our food gets broken down in the mouth?

Where do you think other food molecules that we eat, like protein, get broken down?

What could we do to figure that out?

After updating the Progress Trackers, help students navigate to the next activity. Ask students the following questions found on slide C.

Suggested prompts…..Sample student responses

Do you think that all of our food gets broken down in our mouths? … I’m not sure—probably no. The mouth seems to be breaking down only some types of complex carbohydrates. Don’t we eat other things besides carbs? We eat protein, too.
Where do you think other food molecules we eat, like protein, get broken down?... Maybe in our stomachs? Could we check to see if this happens in other organs in our digestive system?
What could we do to figure that out? … Maybe we could try to find data similar to the data that we looked at from a person’s mouth when they were eating a graham cracker.

Provide several moments for students to share their initial ideas about these questions. Tell students that you were able to access data that shows what happens to a graham cracker as it passes through the rest of the digestive system.

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How to Analyze the Data

Slide D

How to Analyze the Data

The light-colored bar shows the amount of the molecule in the previous location in a healthy person. The dark-colored bar shows the amount of the molecule in the new location in a healthy person.
Record whether the food molecule increases (↑), decreases (↓), or stays the same (＝) from the previous location to the new location.

Say, Recall that we found one food molecule that doesn’t seem to change (fiber), and we found that other types of complex carbohydrates decrease in the mouth while glucose increases. We wanted to look at what happens to food in other parts of the digestive system to see why certain food molecules are increasing while others are decreasing. We thought that if we can figure out what happens in a normal system, it may help us understand more about what’s going wrong in M’Kenna’s body. I pulled together graphs showing how food molecules change during healthy digestion from before it enters a person’s body through multiple organs in the digestive system. Let’s see if we can use these to figure out a typical pattern in what increases and decreases for a healthy person.

Arrange students in groups of three and orient them to their task. Remind students that the goal is to discover relationships between food molecule amounts that increase or decrease during digestion. Pass out a copy of the student reference for lesson 6 found in the student edition and lesson 6 handout to each student.

Present slide D to orient students as to how to record their data. These graphs show how food changes between two locations. As a reminder from Lesson 5, the light green (or light gray if printed in black and white) is the previous amount, while the dark green (or dark gray) is the new amount. In the first graph, the light bars represent what is in the graham cracker before it enters the mouth. Students already analyzed this in Lesson 5 but will do so again here so that they can track the food through the entire digestive system and have built-in support with the data analysis (by viewing a graph that they have already seen). On their handouts, students will record symbols to indicate the amounts that increase, decrease, or stay the same. Consider doing the first two locations together if you feel students need additional guidance. Note that students will attach the half-sheet data table from the handout to their science notebooks after they have analyzed their data. Remind students to update their table of contents.

See the example data sheet attached to the science notebook in the teacher guide.✱

Give groups 8–10 minutes to examine the data and record up, down, or stay the same trends on their data tables. Make rulers available for students. If students ask what the rulers are for, say that other students have asked for them before when looking at these data, and you wanted to make them available in case they thought they might be useful, too.

Then ask students to attach their data table handouts to their science notebooks, so they can write additional ideas around the table as they discuss what they notice. An example is provided in the teacher guide.

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Graham Cracker to Mouth

Slide E

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Mouth to Esophagus

Slide F

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Esophagus to Stomach

Slide G

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Stomach to Beginning of Small Intestine

Slide H

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Beginning of Small Intestine to Middle of Small Intestine

Slide I

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Middle of Small Intestine to Large Intestine

Slide J

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Look for Patterns in Food Molecules

Slide K

How do these patterns help explain why the amount of one type of molecule (e.g., a protein) might be decreasing by the same amount that another type of molecule (e.g., amino acids) is increasing?

Think about the graham cracker moving through the different organs of the digestive system.

Connect food molecules in graphs to their structures on the food molecule cards. As students were examining the food graphs, they may have developed questions about what each of the molecules looks like and how they might be related to each other. Tell students that we can reference back to our Food Molecule Cards to see what these molecules actually look like.

Project slide K and use it to show the molecular representations of the various food molecules. Hand out the food molecule cards in your kit or that you prepared from [material: MR.L5.REF2]. Instruct students to compare and contrast the molecular structures for each of the food molecules. Prompt students to consider the question: How do these patterns help explain why the amount of one type of molecule (e.g., protein) might be decreasing by the same amount that another type of molecule (e.g., amino acids) is increasing in the graham cracker in the mouth?

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Building Understandings Discussion

Slide L

Develop a whole-group record of what we agree on and where we have competing ideas.

What patterns do we notice in the data?

Based on the data, what claims can we make about the functions of each of the organs in the digestive system?

After several minutes, pull students together to report out some of the patterns they have noticed. Project slide J as you do this. Encourage students to come up to the projected image to show what they’ve noticed.

Students should notice that, just as glucose looks like smaller bits of complex carbohydrates, amino acids look like smaller bits of proteins, and fatty acids look like smaller bits of fats.

Suggested prompts…..Sample student responses

Think about the graham cracker moving through the different organs of the digestive system….These models show that certain chemical reactions could be possible, where the same types of atoms would be in the reactant as are in the product.
How do these patterns help explain why the amount of one type of food molecule (e.g., a protein) might be decreasing by the same amount that another type of food molecule (e.g., amino acids) is increasing?... It seems like breaking apart the bigger molecules into smaller pieces would get you certain smaller molecules (e.g., a protein molecule looks like it can be broken apart into amino acids).

Prepare students to engage in a Building Understandings Discussion in which they will make sense of patterns in the data on the food graphs.

Make sense of patterns in the data that we can already explain. Bring the students together to share what they notice from the data. Focus first on patterns that confirm the model ideas already developed in the previous lessons, for example, the water pattern, the fiber pattern, the zeros at the end of the table, and the decrease in other complex carbohydrates and increase in glucose in the mouth. Prompt students to circle these patterns on their tables.✱

Make sense of new patterns in the data. Ask students to share patterns they’ve noticed about which food molecules increase and which decrease. As students share, ask the other groups if they observed the same patterns (e.g., when other complex carbohydrates go down in the stomach, the glucose goes up; both go down in the small intestine).

Purpose of this discussion: Identify patterns in the food data.

Listen for these ideas:

In the middle of the small intestine, all the substances in food start decreasing, except fiber and fatty acids.
Some new substances that weren’t there before start appearing in the stomach (amino acids and fatty acids), and more glucose appears in the mouth than at the beginning.

Suggested prompts…..Sample student responses

Which molecules only go down over time and never go up?... Other complex carbohydrates, proteins, and fats only go down. This seems to happen mostly in the stomach and small intestine.
Which molecules increase and decrease?... Glucose, fatty acids, and amino acids go up in the stomach and the beginning of the small intestine and then go down.
Do any types of molecules appear in the food at any point that weren’t in it before it was eaten?.... There were no amino acids and fatty acids in the graham cracker to begin with, but then they started appearing after they reached the stomach.
Did anyone notice patterns in which one substance increased and another decreased in the same location?...When complex carbohydrates go down, glucose goes up, except in the middle of the small intestine, where they both go down.

If students attach their data tables to their science notebooks before the discussion of patterns, they can circle patterns on their data tables and write an observation about the pattern to the side of it.

An example of one way to record these patterns is shown in the teacher guide. Record a class copy of these patterns to easily reference later in the unit.

Interpret the data to make claims about the functions of each organ. After students have sufficiently analyzed the data, pose the second question on slide L.

Facilitate a Building Understandings Discussion around this question.

Purpose of this discussion: To make sense of the idea that each organ in the digestive system performs a different function and that the digestive system is composed of subsystems each performing different functions.

Listen for these ideas:

Almost all of the food molecules change in the stomach and the beginning of the small intestine. This must mean that the function of the stomach and the small intestine is to help break down food.
Nothing changes in the esophagus. This must mean that the function of the esophagus is not related to the breaking down of food.
Most small food molecules decrease in the small intestine and parts of the large intestine. This must mean that the small intestine and the large intestine are involved in absorption.
Each organ is a subsystem of the digestive system with a particular function.

Prior to beginning the discussion, give students several moments to gather their thoughts either through a Stop and Jot or through a partner talk. Then, begin the discussion by using the suggested prompts located in the teacher guide. ✱

See the teacher guide for additional support.

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Slide M

Discuss with a partner:

We just figured out a lot! How do all of our ideas help us explain what might be going on with M’Kenna? Take a moment to share your initial ideas with a partner.

Summarize what the class has figured out. Take a moment to summarize, or have a student summarize, what we’ve figured out during this lesson. You may wish to prompt students to complete their Progress Trackers for this lesson. They key idea that we figured out was that other organs besides the mouth seem to be breaking down food from big molecules into smaller molecules and that different organs have different functions. Each organ is a subsystem within a larger system that helps the body digest food.

Project slide M and give students just a few minutes to share out their ideas about how what we figured out relates to M’Kenna. Provide time for students to share out their ideas with the whole group. As students are sharing, note the large range of ideas that we have figured out.

Say, It sounds like we have figured out a lot! Maybe it will help us if we can pull all of these pieces together into an explanation for what is happening with a healthy person. That way we can look at all of these ideas in one place to help us figure out what is going on with M’Kenna.

Tell students that, in the next class, we are going to take some time to pull all of our ideas together into an explanation to help us better think about M’Kenna’s case.

Collect copies of the student references to reuse between periods.