Students compare and contrast passive and active transport by playing a game to model this phenomenon. Movement through cell membranes is also modeled, as well as the structure and movement typical of the fluid mosaic model of the cell membrane. Concentration gradient, sizes, shapes and polarity of molecules determine the method of movement through cell membranes. This activity is associated with the Test your Mettle phase of the legacy cycle.

Biology 2e is designed to cover the scope and sequence requirements of a typical two-semester biology course for science majors. The text provides comprehensive coverage of foundational research and core biology concepts through an evolutionary lens. Biology includes rich features that engage students in scientific inquiry, highlight careers in the biological sciences, and offer everyday applications. The book also includes various types of practice and homework questions that help students understand—and apply—key concepts. The 2nd edition has been revised to incorporate clearer, more current, and more dynamic explanations, while maintaining the same organization as the first edition. Art and illustrations have been substantially improved, and the textbook features additional assessments and related resources.

By the end of this section, you will be able to do the following:

Define osmosis and explain its role within molecules
Explain why osmoregulation and osmotic balance are important body functions
Describe active transport mechanisms
Explain osmolarity and the way in which it is measured
Describe osmoregulators or osmoconformers and how these tools allow animals to adapt to different environments

By the end of this section, you will be able to do the following:

Explain why and how passive transport occurs
Understand the osmosis and diffusion processes
Define tonicity and its relevance to passive transport

This comprehensive study guide covers the main terms and concepts needed for a unit on cell transport and homeostasis.

A free CK-12 account is required to view all materials.

This 19-minute video lesson looks at diffusion and osmosis. [Biology playlist: Lesson 36 of 71].

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Great overview of cell membranes. The site presents the information as a tutorial with multiple choice questions to guide the learner. Very well designed site on cell membranes.

Paul Andersen details the first 7 of 13 labs in the AP Biology Curriculum. The following topics are all covered: Artificial Selection, Hardy-Weinberg Equilibrium, Comparing DNA using BLAST, Diffusion and Osmosis, Photosynthesis, Respiration, Mitosis and Meiosis. [13:26]

Students learn about the different structures that comprise cell membranes, fulfilling part of the Research and Revise stages of the legacy cycle. They view online animations of cell membrane dynamics (links provided). Then they observe three teacher demonstrations that illustrate diffusion and osmosis concepts, as well as the effect of movement through a semi-permeable membrane using Lugol's solution.

With an overview of seven topics related to solutions, this .pdf file provides information on everything from osmosis and osmotic pressure to ions in aqueous solution. Other topics include solutions of volatile substances, methods of expressing the concentration of a solution, and more.

A video lesson combined with student group work about the desalination of seawater in areas where there is little access to freshwater.

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.

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.

This activity is a classroom lab where the students gather data on the affect water has on gummy bear candies and develops an experiment based on a new question regarding a not plain water solution. Students will perform calculations and graph their results.

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.

Through two lessons and five activities, students explore the structure and function of cell membranes. Specific transport functions, including active and passive transport, are presented. In the legacy cycle tradition, students are motivated with a Grand Challenge question. As they study the ingress and egress of particles through membranes, students learn about quantum dots and biotechnology through the concept of intracellular engineering.