Cell signaling is one of the more difficult concepts for students to understand in their study of cell biology. To help students better understand the process of cell signaling, from reception to cellular response, a fairly simple signal pathway is used as an example in this case study in which students read a series of instant messages and emails between two friends trying to determine what is causing erectile dysfunction in a prize winning dog. The case was developed for use in an introductory biology course, but could also be used in a cell biology course.

This directed case study involves two "stories," each one concerned with some aspect of osmosis in living cells. Part I is centered around the effects of a hypertonic environment on plant cells, while Part II focuses on the effects of a hypotonic environment on human cells. After reading the parts, students working in small groups evaluate the information and answer the corresponding questions. This case was designed for use in a non-majors biology course, but could be adapted for use in a majors' introductory biology course or a high school biology class.

This directed case study, translated from the original English into Hebrew, involves two "stories," each concerned with some aspect of osmosis in living cells. Part I is centered around the effects of a hypertonic environment on plant cells, while Part II focuses on the effects of a hypotonic environment on animal cells. After reading the parts, students working in small groups evaluate the information and answer the corresponding questions. This case was designed for use in a non-majors biology course, but could be adapted for use in a majors' introductory biology course or a high school biology class.

This case study follows a family's dilemma about how to save money on gasoline. Should they keep their SUV and trade in their Corolla for a hybrid sedan? Going from 28 (Corolla) to 48 (Hybrid) miles per gallon (MPG) should really save money on gas. That's a change of 20 MPG! Or, should they keep their Corolla and trade in their SUV for a minivan? The SUV gets about 13 MPG while the Minivan gets 17 MPG. Students learn how to analyze fuel efficiency in terms of "gallons per miles" driven instead of miles per gallon, and gain graphing and data analysis skills. An extension activity also relates fuel efficiency to greenhouse gas emissions. The case was developed for use in a high school general science course. It could be adapted for use in introductory physics, chemistry, algebra, or environmental science courses at the high school or college level.

In this directed case study, students investigate the cause of death in an incident that occurs late at night in a research lab. The overall goal of the case is to make the abstract concepts involved in cellular respiration more accessible to students. Developed for an introductory biology class, the case could easily be adapted for a more advanced biochemistry class.

This case, developed for a course in human biology, provides students with a context for discussing stem cells and cloning by exploring regeneration in salamanders and the ethical as well as scientific and health-related issues of applying what scientists know about that natural process to humans. Students read the case and then answer questions about cell differentiation and regeneration as they explore the pros and cons of providing natural regeneration in humans versus stem cell transplants for wound and organ repair.

Using a combination of directed case method and role-playing in which students learn about their roles using the jigsaw technique, this case study teaches about the main concepts of stem cell research and therapy and the political and ethical issues surrounding these subjects. The case begins by describing the riding accident that left actor Christopher Reeve paralyzed and ends by posing a final open-ended question that encourages student debate and discussion. The case can be used in a general biology class, an ethics class, or a public policy class.

Focusing on the important role of water in living cellular chemistry, this case emphasizes the general solubility rule, "like dissolves like," which explains how water can serve as a medium for transporting the cell's soluble nutrients and wastes. The case covers how the different interactions between water and glycerophospholipids' polar heads and non-polar tails direct the formation of the cell's membrane bilayer, and teaches students that water is instrumental in positioning amino acids according to their polarities during protein folding. Also reviewed are the chemical reactions of water during photosynthesis, respiration, dehydration, and hydrolysis. The case has been used with nursing students in the second semester of a General, Biological, and Organic Chemistry course. It can also be used as a review of basic biology and chemistry for upper level students in biochemistry.

This case is based on the real-life incident of a boy whose arm was bitten off by a bull shark while swimming off the coast of Florida in the summer of 2001. After the boy's arm was retrieved from the shark's mouth, it was surgically reattached. The case was developed for use in the laboratory section of a freshman- or sophomore-level introductory human anatomy course that takes a regional approach. Several similar clinical cases are used in conjunction with each anatomical region as it is dissected. This particular case study is used during the dissection lab on the upper extremity of the human body.

In this case, students are shown the relevance of chemistry in daily decision-making by taking a look at the popular dietary supplement, s-adenosylmethionine (SAMe), widely used in Europe for depression, arthritis, and liver disease and now available in the United States. The case was developed for use in the first semester of a general biology course taken primarily by non-science majors. Designed to introduce these students to chemistry, it is also good for developing critical thinking skills with regard to the use of dietary supplements, which tend to be popular with many students.

These days it seems like everyone is counting carbs. About 24 million Americans report they have cut carbohydrates from their diet, and 44 million more say they may try a low-carb diet in the next two years. But what do people really know about carbohydrates? This directed case study, designed for use in a large enrollment introductory course, teaches students how to recognize carbohydrates in the foods they eat and to differentiate between different classes of carbohydrates. Students learn how the body utilizes carbohydrates and discuss whether or not eliminating them from their diet can be healthful.

This case reviews concepts of monosaccharide, disaccharide, and polysaccharide and contrasts the structures of different pairs of carbohydrates as well as the structure of sorbitol, a sugar substitute. It also depicts stereo chemistry concepts such as chiral carbon, enantiomer, anomer, Fisher projection, Haworth structure, and glycosidic bonds. In addition, the story associates the similar symptoms related to the gastrointestinal bacteria fermentation of lactose and soluble fibers and compares the enzymes that are responsible for the breakdown of lactose, amylose and cellulose. Furthermore, the case explains the health benefits of consuming insoluble fibers to prevent situations like constipation, diverticulosis, and colon cancer. Finally, the case study highlights the pros (for example, lowering absorptions of fats and glucose to prevent heart disease and the spike of the blood sugar levels after meals) and the cons (such as causing bloating and flatulence) of soluble-fiber consumption.

In this directed case study developed for a biochemistry class, students read about the differences in the dietary preferences and practices for preparing and consuming rice among the three major communities of Malaysia, the local Malays and the immigrant Tamils and Chinese. They then answer a series of close-ended questions about the causes and consequences of thiamin deficiency.

This case study is designed to integrate important aspects of the nervous and muscular system portions of an anatomy and physiology course. Students follow the story of "Kathy," whose symptoms involve both sensory and motor components of the nervous system. The students must recognize the key factors of nerve transmission, examine where there could be interruption, and recognize how the interruption would affect body function. They also need to identify the role that the nervous system plays in muscular function. Through the case, students explore the relationship between both body systems, consider how one affects the other, and discover how function can be affected by external factors.