Speed Dating with Gene Testing

Written by Kelly A. Hogan, University of North Carolina at Chapel Hill

Learning Outcomes:

– Evaluate the strength of the scientific studies presented at direct to consumer personal genomic testing services.

– Practice science communication through a two-minute discussion several times with different partners.

Activity Description: Students (for a class of approximately 30) are assigned prior to the activity one genetic test.  They will use the 23andme website to find out information about the gene test for their assigned trait/disease. During the activity, students follow a sort of “speed dating” protocol in which each student will meet with four other students (5 min each). After the four 5-minute sessions, students will be given an opportunity to choose other students’ presentations they found especially engaging.

Time Needed: 30 minutes in class

Materials Needed: Speed Dating with Gene Testing Homework and DNA Cards Worksheet

Activity Instructions: A week prior to the activity, assign each student to a genetic test (see the list and the student assignment attached). On the day of the activity, set up the classroom– make an inner circle and an outer circle of students, with equal numbers in each circle.  Randomly give five students one of the DNA cards before the activity begins. Each student is initially paired with and talks to another student for a total of 5 minutes. During this time, they each get about 2 minutes to tell each other what they learned.

While talking, each pair should have the list of “question prompts,” but they should not have their own notes out. They can each talk for two minutes straight or they can go back and forth for the 5 minutes. They can decide as a pair initially.

When the buzzer sounds, students in the outer circle rotate and meet with the next student for another 5 minutes. Repeat two more times, such that each student has spoken with four students over the course of 20 minutes. (Rather than a circle, you might try two rows of students in which one of the two rows moves every 5 minutes).

After the four 5-minute sessions, each of the five students with a card chooses one person they found especially engaging by giving them their DNA (a picture card, analogous to a reality show and a rose; see attached). Ask them to explain why. This is meant to get the discussion started, but others might want to also tell what they found most engaging.

Print an image like this to make the DNA cards:

 

 

 

 

 

 

Assessment:

Q: If an Asian male wanted to be tested by 23andme, would the results be applicable to him? Explain why or why not.

A: Yes and no. Many of the tests have been validated by studies of specific ethnicities but the studies have not been replicated in all populations. This does not mean that the results won’t hold true in other ethnicities, but there are limitations to the current knowledge. Nonetheless, many tests have been validated in multiple ethnicities. The site clearly states this for each gene test, so he can look to see which have been specifically validated in Asians.

Using Analogies in Microbiology: The Bacterial Cell as an Entertainment Venue to Illustrate the ATP-binding Cassette (ABC) Transport System

Written by Kristen Z. Swider, Capital Community College

Students in my microbiology class are relatively unfamiliar with the scientific concepts involved in the course and will often attempt to rely on memorization. However, due to the complex nature of the material, it is difficult to access information from the perspective of pure recall. As abstract concepts are discussed throughout a science course, many learners still operating in the concrete stage of development may be lost by a failure to attach understanding to anything of substance. As a result, the concepts are often missed during examinations. There is no requirement that an instructor complicate the approach in order to communicate scientific principles. For these reasons, the use of analogies to illustrate complex processes can enhance a student’s comprehension of the material and make connections that promote lifelong learning. Analogies may be presented to the learner as prepared elements of a lecture or they may be generated by the learners themselves. Self-generated analogies can and do occur spontaneously in discussion. Students are encouraged to develop and present analogies to the class. In either case, the interactive, social process of exploring analogies, whatever their source, contributes to the learning process.

How the ATP-binding Cassette (ABC) Transport System Works

– ATP-binding cassette (ABC) system: This involves substrate-specific binding proteins located in the bacterial periplasm, the gel-like substance between the bacterial cell wall and cytoplasmic membrane.

– The periplasmic-binding protein attaches temporarily to the substance to be transported and carries it to

– Meanwhile, ATP gets broken down into ADP, and phosphate, releasing energy. It is this energy that powers the transport of the substrate, by way of the membrane-binding transporter, across the membrane and into the cytoplasm.

– Examples of active transport by means of ABC systems include the transport of certain sugars and amino acids. There are hundreds of different ABC transport systems in bacteria.

ANALOGY:

The Bacterial Cell as an Entertainment Venue to Illustrate the ATP-Binding Cassette (ABC) Transport System

The players:

Bacterial cell: Entertainment Venue

Substrate: Patron

Periplasm: Outer arena area

Substrate-specific binding protein: Event ticket

Cytoplasmic membrane: Inner arena barrier with turnstiles

Membrane-spanning transport protein: Turnstile

Cytoplasm: Event location (inner arena)

ATP: energy needed to move the turn-stile and allow entry of the substrate (Patron)

– The bacterial cell is the entertainment venue, with the cell wall being the outer boundary of the arena property. Once the patron reaches the arena, he/she can easily migrate through the cell wall to the inner arena (periplasm) since a “ticket” is not yet needed.

– In order for the patron to gain entry into the main arena area of the venue (cytoplasm), he/she must pick up a ticket at a will call/box office. Here in the periplasm, a patron will pick up a pre-prepared ticket (periplasmic binding protein) just before the entering the event.

– Before entering the main arena area, the patron with the ticket (transportable substance and periplasmic binding protein complex) must enter the arena through the turnstile (membrane-spanning transport protein). A turnstile is a form of gate which allows one person to pass at a time. A turnstile can restrict passage only to patrons who provide a coin or a ticket. It can also be made so as to enforce one-way traffic of people.

– Once at the turnstile, the ticket (periplasmic binding protein) gets left behind, and the transportable substrate (patron) can enter the cell via a turnstile.

– As the substrate (patron) moves through the turnstile, energy is required, and ATP is broken down. The patron (substrate) is now in the arena and can be used by the cell.