Diffusion is the net movement of particles from areas of high concentration (number of particles per unit area) to low concentration. In this activity, students use a molecular dynamics model to view the behavior of diffusion in gases and liquids.

Movement of ions in and out of cells is crucial to maintaining homeostasis within the body and ensuring that biological functions run properly. The natural movement of molecules due to collisions is called diffusion. Several factors affect diffusion rate: concentration, surface area, and molecular pumps. This activity demonstrates diffusion, osmosis, and active transport through 12 interactive models.

This pathway explores the concepts of diffusion and osmosis and the factors, like size, that impact the ability of molecules to diffuse across a membrane. There are several opportunities throughout the pathway to experiment with these concepts through simulations.

Changes in energy are associated with both physical and chemical changes in chemistry. This pathway provides resources to explore how energy is related to phase changes, as well as chemical reactions.

Students are challenged to think as biomedical engineers and brainstorm ways to administer medication to a patient who is unable to swallow. They learn about the advantages and disadvantages of current drug delivery methods—oral, injection, topical, inhalation and suppository—and pharmaceutical design considerations, including toxicity, efficacy, size, solubility/bioavailability and drug release duration. They apply their prior knowledge about human anatomy, the circulatory system, polymers, crystals and stoichiometry to real-world biomedical applications. A Microsoft® PowerPoint® presentation and worksheets are provided. This lesson prepares students for the associated activity in which they create and test large-size drug encapsulation prototypes to provide the desired delayed release and duration timing.

A complete, self-paced lesson on homeostasis in the human body, focusing on kidney function. Students work their way through illustrated and animated tutorials, and answer review questions along the way. There is a self-checking quiz at the end of the lesson.

Introduction to Sociology 2e adheres to the scope and sequence of a typical, one-semester introductory sociology course. It offers comprehensive coverage of core concepts, foundational scholars, and emerging theories, which are supported by a wealth of engaging learning materials. The textbook presents detailed section reviews with rich questions, discussions that help students apply their knowledge, and features that draw learners into the discipline in meaningful ways. The second edition retains the book’s conceptual organization, aligning to most courses, and has been significantly updated to reflect the latest research and provide examples most relevant to today’s students. In order to help instructors transition to the revised version, the 2e changes are described within the preface.

Discuss the roles of both high culture and pop culture within society
Differentiate between subculture and counterculture
Explain the role of innovation, invention, and discovery in culture
Understand the role of cultural lag and globalization in cultural change

Using ordinary household materials, student “biomedical engineering” teams design prototype models that demonstrate semipermeability under the hypothetical scenario that they are creating a teaching tool for medical students. Working within material constraints, each model consists of two layers of a medium separated by material acting as the membrane. The competing groups must each demonstrate how water (or another substance) passes through the first layer of the medium, through the membrane, and into the second layer of the medium. After a few test/evaluate/redesign cycles, teams present their best prototypes to the rest of the class. Then student teams collaborate as a class to create one optimal design that reflects what they learned from the group design successes and failures. A pre/post-quiz, worksheet and rubric are provided.

Explore the passive transport process of diffusion.

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The cell membrane is semi-permeable. Sometimes molecules need the help of special transport proteins or an input of energy to help them move across it. When an input of energy is not needed, it is called passive transport. When energy is needed, it is known as active transport. Learn more about passive transport in this learning module produced by CK-12.

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Use this site to learn about basic gas properties including motion, viscosity, and compressibility. Includes links to activities for all ages.

Insert channels in a membrane and observe what happens. See how different types of channels allow particles to move through the membrane.

This activity is designed to give students an understanding of one aspect of what an engineer does and the ability to experience various steps in the engineering design process as it relates to a 3D printing task. Students transform into engineers as they work in teams to carry out a 3D printing task by using a blunt-tip needle syringe to print a line using a variety of colored liquid materials (shampoo, conditioner, aloe, and hand sanitizer) into a small plastic box filled with a gel base. Approximating the work of engineers, the teams observe the interactions between the printed material and the gel base at intervals of 10 minutes and iterate, or change, the ink base as necessary to achieve a goal. Using the dye to color the ink allows students to determine which material will permeate or diffuse throughout the base more effectively. Teams share their results to compare with their classmates. A real-world application for this investigation would be when engineers conduct research to develop new medicines, the goal is for the medicine to make its way through the body in the most effective way so that the body can heal.

Students learn that engineers develop different polymers to serve various functions and are introduced to selectively permeable membranes. In a warm-up activity, they construct models of selectively permeable membranes using common household materials, and are reminded about simple diffusion and passive transport. In the main activity, student pairs test and compare the selective permeability of everyday polymer materials engineered for food storage (including plastic grocery bags, zipper sandwich bags, and plastic wrap) with various in-solution molecules (iodine, corn starch, food coloring, marker dye), assess how the polymer’s permeability relates to its function/purpose, and compare that to the permeability of dialysis tubing (which simulates a cell membrane).

College-level electrical engineering and computer science textbook highlighting the applications of continuum electromechanics.

Students experience the engineering design process as they design, fabricate, test and redesign their own methods for encapsulation of a (hypothetical) new miracle drug. As if they are engineers, teams make large-size prototypes to test proof of concept. They use household materials (tape, paper towels, plastic wrap, weed-barrier fabric, glues, etc.) to attach a coating to a porous "shell" (a perforated plastic Wiffle® ball) containing the medicine (colored drink mix powder). The objective is to delay the drug release by a certain time and have a long release duration—patterned after the timed release requirements of many real-world pharmaceuticals that are released from a polymer shell via diffusion in the body. Guided by a worksheet, teams go through at least three design/test iterations, aiming to achieve a solution close to the target time release constraints.