A Look Into BiotechnologyMariel Pfeifer

Objectives

SWBAT demonstrate the basis of gel electrophoresis as a class.

SWBAT recognize that different restriction enzymes cut DNA at different, but specific, sequences.

SWBAT write a news article describing how a suspect was connected to a crime scene, accurately explaining the basis of gel electrophoresis with correct descriptions of the roles of restriction enzymes, the anode, and agarose in the process.

Gel Electrophoresis

What is it?› a method for separation and analysis of

macromolecules (DNA, RNA and proteins) and their fragments, based on their size and charge

How does it work?› DNA: negatively charged› When gel is connected to power supply,

the DNA migrates to positively charged node (anode)

Gel Electrophoresis

› Smaller fragments travel faster; thus tells us information about the size of fragments

› Include a ladder to help visualize size of fragments

…..So what gives us fragments of DNA?

Restriction Enzymes

Enzymes from different organisms that cut at different, but specific sequences.

So….

Why do we care?› http://www.youtube.com/watch?v=9jCLgGE

Hoa0&feature=related

Crime Scene

What would a gel read out look like if a suspects sample of DNA matched the DNA found at a crime scene?

What if the suspect was innocent?

Review› What is the role of restriction enzymes

in gel electrophoresis?› Where would BamHI cut? What about

EcoRI?› Why does DNA migrate toward the

positively charged node?› What is the name of the node that DNA

migrates towards?› What would a gel look like if it contained

DNA from a suspect that matched the DNA found at a crime scene?

Restriction Enzyme Table

Lesson Plan Part 1

Mariel Pfeifer EDSE 4275 November 28, 2012 Microteach Lesson Plan A Look at Biotechnology Target Grade: 10th Cross-Cutting Concept(s): Change, Constancy & Measurement Standards Addressed: SC11.1.2; SC11.2.4; SC11.3.2   Vocabulary Introduced: Gel electrophoresis Pipette Cathode Anode Restriction enzymes Agarose Biotechnology Hook: For today’s hook, the following two pictures will be projected onto the board. As students enter the room they will be asked to remember their observations

about the pictures to figure out what the picture might be of.    Real-World Application: The focus of this lesson is real world application of DNA and its properties for use by science. Students will see how biotechnology can be used to answer

societal questions. Objectives: 1. SWBAT demonstrate the basis of gel electrophoresis as a class. 2. SWBAT recognize that different restriction enzymes cut DNA at different, but specific, sequences. 3. SWBAT write a news article describing how a suspect was connected to a crime scene, accurately explaining the basis of gel electrophoresis with correct

descriptions of the roles of restriction enzymes, the anode, and agarose in the process. Agenda—written on board prior to class 1. Hook/Pre-Assessment (5 minutes) 2. Gel Electrophoresis Activity (5 to 7 minutes) 3. Gel Electrophoresis Lecture/Review (2 to 3 minutes) 3. Writing Exercise (2 minutes)

Lesson Plan Part 2

Questions Low Level What charge is carried by DNA? At what sequence does BamHI cut? Mid Level How is the agarose gel obstacle course similar and different from what actually occurs during gel electrophoresis? What is another instance in which molecules are separated based upon the size of their fragments? High Level What would you predict to be true about the samples in the gel electrophoresis results pictured at the beginning of the class?   Activities—class demonstration; mini-lecture; science writing Hook. To engage the class, the hook described above will be used. The teacher should ask students to describe what they think the connection between the two pictures is. If students

are struggling, point out to them the words “bps” and “sequence” that should help students to connect the pictures to DNA. Pre-Assessment. As a means of pre-assessment, the teacher will ask the students the following true or false questions. Students who think an answer is true will raise their hands. The

teacher will record these responses. 1. True or False: Restriction enzymes all cut at the same sequence of DNA. FALSE 2. True or False: Because DNA is positively charged, it migrates toward the anode during gel electrophoresis. FALSE 3. True or False: The use of restriction enzymes and gel electrophoresis can help investigators match DNA from a crime scene to DNA of a suspect. TRUE The teacher will provide instructions to the class about the gel electrophoresis activity. When instructed to do so, students should line up on the same side of the room (left side). From

there the teacher will ask them to pair off into groups of two with arms linked. When the teacher says go, the students should WALK (not run) quickly to the opposite side of the room. Student should “zig-zag” through the tables, they can’t walk in a straight line. Once 15 seconds has passed, the teacher will say, “STOP.” Students should remember where they ended up in their journey.

The class will line up on the left side of the room. When everyone is situated and rules are re-stated the teacher will instruct the class to begin zig-zagging through the class. After 15 seconds and when student positions have been either marked or remembered. The class will line up along the left side of the room, again.

This time, the teacher will break students up into group of 4. Students will complete the same steps as described above. After 15 seconds, students will be asked to stop. They will mark these locations.

After both locations have been marked, the teacher will ask a student to summarize what just happened. › When in smaller groups, students were able to travel further across the room than they were able to do in larger groups. › This is the basis of gel electrophoresis, the teacher will ask the students to return to their seats

Now, the teacher will introduce the content base for gel electrophoresis. Students will be asked to take notes, appropriately in their science journals. They will use the information presented in the lecture to write news articles after the review. Students will need to pay special attention to the role of restriction enzymes, the anode and agarose for this piece of biotechnology to work.

Review. After the content is presented in the mini-lecture, the teacher will review the information from both the activity and the lesson with the students. The following review questions will be used:

› What is the role of restriction enzymes in gel electrophoresis?› Where would BamHI cut? What about EcoRI› Why does DNA migrate toward the positively charged node?› What is the name of the node?› What would a gel look like if it contained DNA from a suspect that matched the DNA found at a crime scene?

Lesson Plan Part 3

Post-Assessment. The students will be asked the same questions as described in the pre-assessment. Students will be given remaining time to write articles. Student writing will be assessed with the attached rubric. Extension. An awesome extension would be to have students run a gel electrophoresis, depending upon the technology

available to the school. If the gel electrophoresis equipment is not available, a relevant extension would be for students to research and describe the basis of gel electrophoresis in a diagram format. Student could also investigate restriction enzymes and describe how they are used by scientists.

Materials Projector Tape Stopwatch (or some sort of timing device) Mini-lecture slides Science Journals News Article Rubric Safety Considerations This lesson does not contain many additional safety concerns, besides those for general classroom safety. Be sure to inform

students that they need to walk, not run, while participating in the gel electrophoresis activity.   Differentiation For students with writing disabilities, extra time may be granted for the students to complete their writing assignment. If

possible, the text-to-speech software (Dragon Naturally Speaking) can be used by students to dictate their news articles. If needed, a copy of the lecture notes will be provided to students.

For ELL students, the lesson can be differentiated to support science writing skill development. In these circumstances, it would be appropriate to allow students to write their articles in their first language. Or, to provide a template for students to use, where students could fill-in-the blanks with the vocabulary introduced in today’s lesson. A copy of the lecture notes would also be provided.

For students with physical disabilities, depending upon the nature of the disability, the teacher may add additional time that the class is “migrating” during the gel electrophoresis activity. Or, the teacher may change the rules of the game to allow students to move in straight lines across the classroom. Teachers should ensure that there is adequate room for students with mobility aids to move around the room.

Lesson Plan Part 4

Assessment: Formative and Summative 1. The pre and post-assessment described above will be used to assess student learning (formative). 2. Students will submit their news articles to be graded using the attached rubric. 5 points. (summative).

  News Article Imagine that you are a reporter for a newspaper. A murder suspect has recently been linked to the scene of the crime in your community! It is up to you to inform

the public about what methods are being used to test the DNA found at the crime scene to the DNA sample supplied by the suspect. A few notes about your article: It should be ½ to a page in length with paragraphs and appropriate conventions. Describe the basis of gel electrophoresis that a member of the public would be able to understand! But be sure to include the role of restriction enzymes, the way in

which DNA can migrate through a gel and how agarose impacts that migration. Your suspect can either be guilty or innocent! It’s up to you! But your description must be accurate of whatever result you deem to have occurred. A diagram will get you one whole point! Check out the rubric below for more information. Category Unsatisfactory Needs Improvement Satisfactory Audience-Appropriate Content The tone of the article is not appropriate for the intended audience. The article may meet the needs of the audience, but does not fully realize the connection between gel electrophoresis and a crime scene. The article accurately meets the needs of the audience. The article is imaginative and the reader is able to visual the gel electrophoresis results. (1 point) Description of Science Content The article does not describe gel electrophoresis in a way the reader can understand. The article meets all of the expectations of the Satisfactory category, but may need improvement in the one of the areas of specific mention. The basis of gel electrophoresis is described fully, with specific mention of: restriction enzymes, basis of DNA migration in a gel; and agarose. (1 point) Quality The student's work is thrown-together and no diagram is included. The student's work appears to be rushed and not well organized. A diagram is included but does not serve to help the reader understand the process of gel

electrophoresis. It is obvious that the student took time to write their article. A diagram may be included to help the reader visualize either the results or gel electrophoresis. (2

points) Conventions More than 3 errors are made. More than 3 errors are present. 0 to few errors present. (1 point)