Lesson The Keepers of the Gate Challenge

Quick Look

Grade Level: 10 (9-11)

Time Required: 15 minutes

Lesson Dependency:

Subject Areas: Algebra, Biology, Chemistry, Data Analysis and Probability, Life Science, Measurement, Problem Solving, Reasoning and Proof, Science and Technology

Photo shows a woman lying sick in a bed with a tissue in her hand.
Does salt water help a sore throat?
Copyright © 2004 Microsoft Corporation, One Microsoft Way, Redmond, WA 98052-6399 USA. All rights reserved. http://office.microsoft.com/en-us/images/results.aspx?qu=sick&ex=1#ai:MP900430501|mt:2|


Students are presented with a real-life problem as a challenge to investigate, research and solve. Specifically, they are asked to investigate why salt water helps a sore throat, and how engineers apply this understanding to solve other problems. Students read medical journal articles and watch a TEDx Talk to learn more about nanotechnology applications. After students reflect and respond to the challenge question, they conduct the associated activity to perform journaling and brainstorming.

Engineering Connection

The ability to identify a problem and work with others to determine a solution is the core of the engineering design process. Students use their problem-solving abilities and team brainstorm session to figure out how they will solve the challenge: designing an experiment to test their hypothesis. Students recognize a problem and work through different channels to find a way to solve it. Additionally, students learn about bionanotechnology, a field of study that advances biomedical engineering technology.

Learning Objectives

After this lesson, students should be able to:

  • Define nanotechnology, nanoscience and biomedical engineering.
  • Explain how quantum dots are an example of nanotechnology used to detect cancer.
  • Define the challenge associated with this unit.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

  • Identify the design problem to solve and decide whether or not to address it. (Grades 9 - 12) More Details

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  • Optimize a design by addressing desired qualities within criteria and constraints. (Grades 9 - 12) More Details

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Have you ever wondered why certain things work in your body? And, have you ever wondered how you can make things in your body work better? It is interesting to realize that many of the things that we wonder about have a unique scientific reason that makes them possible.

In this lesson, you will be presented with a problem that many of you have probably experienced and you will be challenged to figure out its scientific roots and solutions. The ability to identify a problem and work with others to determine a solution is the core of the engineering design process. In this case, you will ultimately design an experiment to test your hypothesis. You will listen to a doctor and read an article about quantum dots. (This is part of the Multiple Perspectives portion of the legacy cycle.)

This is your Grand Challenge: "You are spending the night with your grandmother when your throat starts to feel sore. Your grandma tells you to gargle with salt water and it will feel much better. Thinking this is an old-wives tale, you scoff, but when you try it later that night it works! Why?"

Before you can solve a problem like this, you need to first understand the scientific principles surrounding the problem. This is one of the first steps engineers take: brainstorming and researching content involving the problem. In this case, we will first listen to Timothy Hanks discuss the importance of nanotechnology and read articles on how it can be applied to solving medical problems, such as a sore throat. 

Lesson Background and Concepts for Teachers

Using the Introduction/Motivation content, present students with the Grand Challenge question, which they will later use to Generate Ideas and brainstorm in the associated activities, "Cell Membrane Journal and Brainstorm." and Grand Challenge Journaling and Brainstorming.

Show students the following video and articles so they gain a better understanding of the applications of nanoscience and nanotechnology:

Conclude by describing how biomedical engineers use these concepts to help further explore the origins of problems with the human body. Biomedical engineers also develop better nanotechnology that is applied to the detection of diseases within the body. Then relate this back to the challenge question: understanding why saltwater helps our sore throats feel better. Explain how understanding the reasons behind a sore throat and defining possible solutions relies on obtaining a better understanding of the nanoscience involved at a cellular level.

Associated Activities

  • Grand Challenge Journaling and Brainstorming - Students journal their thoughts and responses to the questions that arise from the unit's Grand Challenge: "What are your initial ideas about how this challenge can be answered? What background knowledge is needed? Have you tried this before?" Then the class brainstorms to reach consensus on the main ideas that need to be explored to solve the challenge question.


bionanotechnology: The merger of nanotechnology and biology: using nanotechnology to further study the field of biology and control various aspects within organisms.

nanoscience: The study of matter on a nano-scale.

nanotechnology: Tools developed to study and work with matter sized from 1 to 100 nanometers.

quantum dots: Nanoscale semi-conductors that can be used in medical imaging.


Pre-Lesson Questions: Evaluate students' prior knowledge by asking them to reflect and respond to a few questions about the lesson topics. Example questions:

  • What is nanoscience?
  • How might nanoscience help understand why you have a sore throat?
  • What do engineers do?
  • Why do you need to know about nanoscience?

Homework: Begin brainstorming possible hypotheses for why salt water helps sore throats feel better.

Additional Multimedia Support

TEDx Talk with Timoty Hanks: https://www.youtube.com/watch?v=k02DC7K52Ek

"The Science Behind The Nanotechnology Phenomenon" article: https://www.azonano.com/article.aspx?ArticleID=1935

"Applying Nanotechnology to Human Health: Revolution in Biomedical Sciences" article: https://www.hindawi.com/journals/jnt/2009/184702/

Link for "Finding Cancer Cells with Quantum Dots" article: https://pubs.acs.org/doi/pdf/10.1021/ac041673t


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© 2013 by Regents of the University of Colorado; original © 2010 Vanderbilt University


Melinda Higgins

Supporting Program

VU Bioengineering RET Program, School of Engineering, Vanderbilt University


The contents of this digital library curriculum were developed under National Science Foundation RET grant nos. 0338092 and 0742871. However, these contents do not necessarily represent the policies of the NSF, and you should not assume endorsement by the federal government.

Last modified: June 16, 2019

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