In this lesson, students will study an that describes how researchers at the University of Sydney have discovered a correlation between artificial sweeteners, like sucralose, and an increased appetite. There are estimates that over 4,000 types of food contain sucralose. Billions of people around the world consume artificial sweeteners in hopes of losing weight, and until this study, little has been known about how these sweeteners affected the brain. This lesson is designed to support reading in the content area; it includes a note-taking guide, text-dependent questions, a writing prompt, answer keys, and a writing rubric.
Subject(s): Science, English Language Arts
Grade Level(s): 11, 12
Document Camera, Computer for Presenter, Computers for Students, Internet Connection, LCD Projector, Speakers/Headphones
Resource supports reading in content area:Yes
Keywords: sugar, sucralose, artificial sweetner, obesity, weight loss, calories, brain, informational text, text complexity
Lesson Plan Template: General Lesson Plan
Learning Objectives: What should students know and be able to do as a result of this lesson?
- Effectively communicate the results of a scientific investigation.
- Cite specific and relevant text evidence to support analysis of the text.
- Use various vocabulary strategies to define academic and domain-specific words in the text.
- Construct a written response that clearly establishes the main point(s), contains relevant textual evidence to support the main point, utilizes transitions to maintain flow, effectively uses domain-specific vocabulary, and provides an appropriate conclusion.
Prior Knowledge: What prior knowledge should students have for this lesson?
In regards to science:
- Students should have a good background on scientific methods.
- Teachers might wish to have students use the CPALMS "Scientific Method Tutorial and Virtual Experiment" (ID 24388) to increase their background knowledge on scientific methods.
- Students should have a basic background in chemistry or biochemistry. Topics that would be helpful would include bonding, hydrolysis, and enzymes. These terms aren't used specifically in the article, but understanding these concepts will allow for a deeper understanding of the research that is described in the text students will read.
- This 2-minute video titled "Hydrolysis and Dehydration Synthesis" from RicochetScience explains and illustrates dehydration synthesis and hydrolysis. This concept will help the students realize that if your body doesn't have the ability to break down a molecule, you can't get any energy from it.
- Sucrose is the correct name for table sugar. This 2-minute video from McGraw-Hill titled "Enzyme Action and the Hydrolysis of Sucrose," uploaded by Deckara Fluke, shows how sucrose is broken in half. Sucralose, the artificial sugar, cannot be broken in half, therefore no energy is released. However, the body works on chemistry so sucralose can still send signals, but the body does not have the ability to break it down.
- If students don't have a recent background on enzymes, this seven-minute video titled "What are Enzymes - How do They Work?," uploaded by MTS Video Marketing, may be useful.
- Students should also have a basic understanding of carbohydrates. Students should know that carbohydrates, like sucrose (table sugar), are used for energy.
In regards to literacy skills:
- Students should have prior experience utilizing various vocabulary strategies to determine the meaning of unknown words in a text, including use of context clues and dictionary skills.
- Based on the writing rubric provided with this lesson, students should be able to respond to a writing prompt in a clear, organized manner that includes use of an introduction to establish the main point(s), a body paragraph(s) that support the main point(s) and includes relevant and specific textual evidence, and a conclusion that supports the main point(s).
- Students should have some awareness that use of transition words or phrases can help a piece of writing flow smoothly from one point or idea to the next. Teachers might wish to provide students with a sheet of transitions to help them. This site by Smart-Words provides transitions teachers might provide.
Guiding Questions: What are the guiding questions for this lesson?
- What is the question/problem being researched?
- Why do artificial sweeteners increase your appetite? As stated in the introduction, previous studies have already shown a link between artificial sweeteners and an increase in appetite. This research by the University of Sydney was the first to find out why. Scientists were able to find a pathway in the brain that stimulates the appetite if the caloric consumption vs. food intake does not match up.
- What is the data that supports the link between artificial sweeteners and increased appetite? What animals were tested in the research?
- Data shows that appetite in fruit flies increased 30% when artificial sweeteners were consumed over a prolonged period of time, and that mice experienced a similar "significant increase in food consumption" after seven days. Multiple trials of fruit flies and mice were tested. This shows both primitive and more complex mammals had the same response. Researchers were able to determine that sucralose increased appetite. The brain was able to sense that even though it was tasting something sweet, the number of calories didn’t match up. There were not enough calories, so the brain instructed the animal to eat more so it didn't starve. Researchers also found that artificial sweeteners promoted hyperactivity, insomnia, and decreased sleep quality. These are also behaviors consistent with how a body can react when it thinks it is starving.
Teaching Phase: How will the teacher present the concept or skill to students?
- Begin the lesson by posing a general question to the class: Where do we get our energy from?
- Students may answer: food or possibly ATP. Students with a good chemistry background may say from the breakdown of food, molecules, or even the splitting of bonds. Hydrolysis breaks the bonds and allows for energy to be released. Be sure to emphasize that animals can only get energy from molecules that they can break down or split the bonds between the atoms.
- Next ask students: What molecule does our body prefer for energy?
- Student answers will vary. The body prefers glucose, because it is easy to break down.
- Then ask students: What is a calorie?
- Student answers will vary. A calorie is a measure of energy. Any molecule with atoms bonded together have the ability to release energy.
- Finally ask the students: Why don't artificial sweeteners have calories? They are made of atoms bonded together.
- Student answers will vary. Artificial sweeteners don't have food calories because our bodies have no way of breaking the bonds that hold the atoms together. Usually, our bodies use enzymes, a type of catalyst, to help us breakdown molecules. Our body does not have the enzyme to break artificial sweeteners down, so they travel through our body whole.
- End the discussion by informing students that they will be reading about how researchers from the University of Sydney have discovered how artificial sweeteners affect the brain and appetite.
Guided Practice: What activities or exercises will the students complete with teacher guidance?
- Provide each student with a "Why Artificial Sweeteners Can Increase Appetite" from ScienceDaily. For class discussions that will follow, it might be helpful to have students number each paragraph.
- Provide each student with a note-taking guide.
- Before students begin reading, point out the summary at the top of the page, the photograph and caption, and the introduction in enlarged font below the caption.
- Have students fill out the note-taking guide as they read the text. This can be done individually, in pairs, or in a small group. Students can complete the vocabulary portion after their first reading of the text. The teacher should monitor students as they work and provide support and guidance as needed. Students should have access to print or online dictionaries.
Formative Assessment (How will teachers check for student understanding?):
- Teachers can check students' understanding by collecting students' completed note-taking guide, checking their work, providing written feedback, or grading the assignment. Or, teachers can have students share out their responses and the teacher can provide verbal corrective feedback, allowing students to make corrections to their work during the discussion.
- For discussion on students' answers to the defined vocabulary words, teachers are encouraged to not only ask students to explain the meaning they determined for a word, but the strategy they used to arrive at that meaning. This will allow the teacher to provide alternative suggestions as to how the student could have arrived at the correct meaning of the word.
Common errors/misconceptions to anticipate and how to respond:
Students may believe that if your body cannot break down a molecule, then it can't interact with your body. Even though sucralose isn't broken down, it can still react with other molecules in your body.
Independent Practice: What activities or exercises will students complete to reinforce the concepts and skills developed in the lesson?
Provide each student with a copy of the text-dependent questions to complete. Students should be reminded to continually refer back to the text and to use relevant and specific evidence from the text to support their answers.
Formative Assessment (How will teachers check for understanding?):
Teachers can check students' understanding by collecting students' answers to the text-dependent questions, checking their work, providing written feedback, and maybe grading the assignment. Or, teachers can have students share out their responses and the teacher can provide verbal corrective feedback, allowing students to make corrections to their work during the discussion.
Common errors/misconceptions to anticipate and how to respond: Please see the text-dependent questions sample answer key.
Closure: How will the teacher assist students in organizing the knowledge gained in the lesson?
- Before students complete the writing prompt for the summative assessment be sure to review responses to the text-dependent questions as a class, including covering the misconceptions and key points described in the sample answer key.
- After students' written responses for the summative assessment have been graded and returned with feedback, teachers might wish to use the provided sample response with the class. Students who are struggling writers can benefit greatly from seeing a well-organized, detailed written response. The teacher could show the sample response on an overhead orwithanLCD projector and discuss some of the following:
- Have students examine the introduction and conclusion to see how the author established and wrapped up her argument. Point out how the author's claim (the main point of the argument) supports the writing task that was given in the writing prompt.
- Have students identify the use of textual evidence (both direct quotes and paraphrased information) in the two body paragraphs that help support the author's argument.
- Have students identify effective use of domain-specific vocabulary (e.g., sucralose, replicated, neuronal network) and academic vocabulary (e.g., prolonged, consuming, chronic, stimulates).
- To close the lesson, provide students with an exit ticket. Ask students to communicate the most significant piece of evidence from the scientists' research that they obtained from reading the article, and have them explain why this piece of evidence is significant.
- Students will individually respond to the writing prompt. They should be directed to respond with a multi-paragraph response, with a clear introduction, body section, and conclusion. They can refer back to the text as they construct their response.
- Provide students with a copy of the rubric and go over the rubric with them so they will know how their written response will be assessed.
- Go over the following writing prompt with students and make sure students understand what the prompt is asking them to address:
- Imagine that your mom has been trying to lose weight for several years. She drinks a lot of diet soda and has been using artificial sweeteners with all her tea and coffee. Communicate the evidence from the article with your mother on how the removal of artificial sweeteners could help her lose weight. Be sure to give your mom specific evidence from the text to help validate the results of the experiment.
- Teachers will use the rubric to assess students' written responses.
Specific suggestions for conducting the Formative Assessment can be found in the Guided Practice and Independent Practice phases of the lesson.
Feedback to Students
Specific suggestions for providing Feedback to Students can be found in the Guided Practice and Independent Practice phases of the lesson where it says, "Common errors/misconceptions to anticipate and how to respond."
Accommodations & Recommendations
The text's grade band recommendation reflects the shifts inherent in the Florida Standards and is based on a text complexity analysis of a quantitative measure, qualitative rubric, and reader and task considerations.
Source and Access Information
Name of Author/Source: Jennifer Heflick
District/Organization of Contributor(s): Brevard
Access Privileges: Public
* Please note that examples of resources are not intended as complete curriculum.