Cell Biology/Chemiosmosis is one of a series of interactive web-based lessons designed to give introductory undergraduate biology students opportunities to connect biology concepts. Each lesson is a series of screens that breaks the topic down into simple steps and then illustrates the connections between the steps to present the completed concept or process. Chemiosmosis is a difficult process for students to grasp; this site can be used as a supplement to the lecture to allow students to review the topic at their own pace and as many times as desired. It is divided into three lesson topics that cover the components needed for chemiosmosis using a prokaryotic cell, how it works in eukaryotic cells, and how the process might have evolved. A very good help screen is provided to help students use the lessons. The larger site containing the entire series will be very useful at the introductory level. Subjects include the components of chemiosmosis, organelles involved (chlorplasts and mitochondria) and the endosymbiosis theory of the evolution of chemiosmosis in eukaryotes. Animations of the electron transport chain and ATP sythase are included.
The major goal of this lesson is to help students understand the series of events that occur inside cells/cell organelles that allows the cell to harvest energy from oxidation reactions and synthesize ATP. Each of the three lesson topics addresses portion of the larger process and contains specific learning objectives.
Target Student Population:
Undergraduate and High school (AP level)
Prerequisite Knowledge or Skills:
Students will need to have a basic understanding of energy as applied to living systems as well as basic knowledge of the difference between prokaryotic and eukaryotic cells.
Type of Material:
This site could be used in many ways. 1. As the basis of a classroom lecture presentation. 2. As an out-of-class assignment before the topic is covered in class. 3. As a study tool for students after topic is presented in class.
Evaluation and Observation
Site is highly interactive as student places components in correct position.
Questions asked throughout lessons help student get feedback on understanding of concepts/process.
Animations clearly connect the different parts of each process into a coherent whole.
Excellent graphics with high quality practice questions embedded.
Covers the most important parts of chemiosmosis, and does so by asking students challenging questions.
Evolution of eukaryotic organelles is especially well done, really probing which prokaryotes were most likely to be symbiotic with early eukaryotes.
Contains links to defintions of terms.
Some of the questions may be too difficult for some undergraduates, but they could always choose answers randomly and learn what the correct answer was.
Accuracy of table comparing mitochondria and chloroplast needs to be reviewed.
Discussion of osmosis does not include why the water diffuses through the membrane to create a concentration gradient.
Potential Effectiveness as a Teaching Tool
Clearly demonstrates relationships between elements of each concept.
The site can be used in several waysas a direct teaching tool in a distance learning course, as a lecture outline, as a review and study tool for students after topic covered in class.
Some of the questions asked promote problem solving by student.
Completion of plans for links to assessments and image/animation data bases will greatly enhance the usefulness of the site.
Tremendous potential for students to review the main concepts in chemiosmosis. Gets at the underlying fundamentals, and asks challenging questions of the students.
Goals of each unit are clearly stated and the tutorial and questions match well with the stated goals.
Could write exam/assignment questions based on the tutorial.
Would be difficult for a student to follow without some previous knowledge of the big picture behind metabolism and ATP production.
A flash animation of osmosis and chemiosmosis would help on the first page to distinguish the two for students.
Ease of Use for Both Students and Faculty
Easy to navigate, pages load quickly, no dead links, well organized.
Could easily copy individual pages, images or flash animations into your own course materials.
Instructions clear, especially when manipulating components and entering animations.
Instructors manual available; summarizes the contents of each of the lesson topics.