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Peer Review

Connecting Concepts: Cell Biology/Thermodynamics

by Robert Jeanne , Jan Cheetham


Overall Rating:

4.5 stars
Content Quality: 4.3 stars
Effectiveness: 4.6 stars
Ease of Use: 4.6 stars
Reviewed: Sep 16, 2005 by Biology Editorial Board
Overview: Cell Biology/Thermodynamics 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. Thermodynamics (sometimes referred to as energetics) 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. This simulation/tutorial consists of five topics. In topic 1, students make decisions for a paramecium living in a Petri dish that will determine if it will have enough energy to survive and reproduce. Students will 1) decide whether the paramecium will eat, swim, or reproduce based on its available energy and the amount of energy required for each activity; and 2) Learn about cellular processes that require energy. In topic 2, students follow energy conversions in Euglena, during photosynthesis, respiration, and cellular work. Students will: 1)review definitions and properties of endergonic and exergonic processes; 2) explain, in qualitative terms, free energy changes in the universe, photosynthesis, respiration and cell work; and 3) identify the type of work (chemical, mechanical, etc.) being done in a number of cellular processes. In topic 3, students solve a mystery: where does ATP’s energy go in the glutamine synthetase reaction? Students will: 1) “interview” molecules to learn how ATP’s energy was released and absorbed in the ATP-coupled reaction; 2) reconstruct events leading to and from a high energy reaction intermediate; 3) identify which molecules (reactants, products, enzyme) got some of ATP’s energy. In topic 4, students learn what enzymes can and cannot do in a reaction by “hiring” an enzyme for the “job” of catalyst from a set of candidates that may be exaggerating their “qualifications.” Students will: 1) evaluate the claims of each enzyme to determine if they violate the chemical and thermodynamic properties of enzymes; and 2) select the “candidate” who is honest about what a catalyst can do in a reaction. In topic 5, students compare the energetics of photosynthesis, cellular respiration, and cellular work. Students will: 1) complete a review table that summarizes the energy inputs, outputs, free energy change, etc. of these processes; 2) review free energy change, deltaG, enzyme involvement, energy input and output.
Learning Goals: The major focus of this lesson is to acquaint students with energy processes and conversions and how these process relate to living organisms. Each of the five lesson topics addresses a portion of the larger process and contains specific learning objectives.
Target Student Population: High school (AP level) through college undergraduate.
Prerequisite Knowledge or Skills: Students will need to have a basic understanding of chemistry as it applies to living organisms in order to understand this lesson. Students will also be expected to have read the text assignments on this topic.
Type of Material: Tutorial
Recommended Uses: 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.
Technical Requirements: Flash 6.0

Evaluation and Observation

Content Quality

Rating: 4.3 stars

  • A well designed tutorial illustrating the importance of thermodynamics on cellular processes.
  • Good quizzes on the role of enzymes in catalyzing reactions and intermediates in reactions.
  • Important topics for most introductory biology courses.
  • Throughout the lesson, the student is required to manipulate objects to get the correct answer before going on.
  • 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.

  • The units don't flow together as well as in some other tutorials. The unit on paramecium swimming to find food was not particularly informative, and then it jumped to thermodynamics in a plant.
  • Question on "How energy is absorbed and converted in Euglena" may lead to some incorrect information about energy loss in the universe.
  • The matching question is lesson topic 2 is confusing.
  • Last screen in Topic 3 is incomplete.

Potential Effectiveness as a Teaching Tool

Rating: 4.6 stars

  • Interactive to a degree, asks challenging questions of students that get to fundamental underlying concepts in thermodynamics.
  • The paramecium "energy game" is an excellent way to get students thinking about energy and life.
  • Written at an appropriate level for most undergraduates.
  • Summary section (Topic 5) is a good review of the materials in the tutorial.
  • Clearly demonstrates relationships between elements of each concept.
  • The site can be used in several ways - as 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.
  • Some of the questions asked will be very challenging for introductory students.
  • Completion of plans for links to assessments and image/animation data bases will greatly enhance the usefulness of the site.

  • Not particularly inquiry-based, mostly a collection of questions for students to answer given a scenario.
  • Only somewhat engaging topics, a medical theme might have worked better.

Ease of Use for Both Students and Faculty

Rating: 4.6 stars

  • Runs smoothly, good graphics.
  • Well organized.
  • Instructions clear, especially when manipulating components and entering animations.
  • Instructors manual available; summarizes the contents of each of the lesson topics.
  • Glossary available for selected terms

  • One defective link on page 3 of topic 3 on ATP, there is not a question.
  • No open source code for re-use.

Other Issues and Comments: This series of lessons has outstanding potential for use by faculty and students everywhere. The concepts are broken down to simple parts and then reassembled by an interactive process and animations into a whole.