Science Tutor: April 2007

Monday, April 16, 2007

4th Marking Period Chemistry Project

Chemistry of Materials – Coordinated Science II – 4th Marking Period Project

DUE TUESDAY, MAY 8, 2007

Assignment and Objective: Understanding atomic and molecular structure expands our knowledge of the nature of the material world and advances the technological sophistication of society. Each student will learn about the history and chemical make-up of a commonly used material, and present that information to the class. Students will also be responsible for learning about the topics that are presented by others.

Procedure:

1. Each student will be assigned a topic by lot (random drawing from a container). Each student in the class will have a different topic to research, which will be one of the following topics:

∙Amber∙Henna∙Plastic Bags∙Chili peppers∙ Erasers∙ Honey∙Polyurethane foam
∙Margarine∙Food Coloring∙Food Preservatives∙Citronella Oil∙Kava
∙Artificial Sweetners∙MSG∙Licorice∙Chicken Eggs∙Catnip∙Kitty Litter∙JELL-O®
∙Bug Sprays∙Rain Coats∙Golf Balls∙Sticky Notes∙Soap Bubbles∙Sunscreens
∙Marshmallows∙Gasoline∙Artificial Snow∙Teeth Whiteners∙New Car Smell
∙Motor Oil∙Ice Cream∙Glass∙Opal∙Shampoo∙Shower Cleaners∙Pencils and Pencil Lead
∙Fireworks∙Fluoride∙Aircraft Deicers∙Chocolate∙Silly Putty∙Self Tanners
∙Hair Coloring∙Cheese Whiz∙Asphalt∙Baseballs∙Lycra/Spandex∙Lipstick
∙Light(glow)sticks∙Ink∙Cement∙Tyvec∙Kevlar∙Paper

This is an independent, at-home research project.

2. Each individual student will present their research information to the class by presenting a brief oral presentation and an 11” by 17” Shutter Fold (foldable) display of their work, which is constructed according to the attached directions and as demonstrated by the teacher. The display is to include the following:

1. a history of the use and invention of the material.

2. diagrams/drawings of the chemical structures, or chemical formula of all the ingredients that make up the material.

3. the health hazards and health benefits of the material.

4. a biography of the inventors of the materials, or a description of a company that manufactures the material.

5. a copy of a patent from http://patft1.uspto.gov/netahtml/PTO/search-bool.html or
http://www.google.com/patents where the name of the material, or the important chemical ingredient in the material, has been put in as a search term.

6. A completed information sheet about the patent.

7. pictures of the material, or actual samples of the material.

8. The student’s research information should include a bibliography (MLA format). This is a formal presentation. The writing and project should reflect a student’s best effort.

3. During the oral presentations, the audience will take notes about each of the materials; everyone will be responsible for knowing the important facts about each material and will graded on their proper participation as an audience.

4. The finished project is due on Tuesday, May 8, 2007. The Middletown Cavalier Chemical Science Meeting will commence on May 9 and run through May 11 to allow for all students to have an opportunity to present the important information about each topic. Late projects will not be accepted. Students must be prepared to present on May 9. The project is 20% of the marking period grade and will be evaluated as follows:
∙ Visual Aid/Foldable presentation 20 points

∙ Important information included 18 points

∙ Well organized 06 points

∙ Pictures of Material 06 points

∙ Copy of Patent with Completed Information Sheet 20 points

∙ Bibliography – must have two sources 12 points

∙ Audience Notes 18 points

____________________________________________________________________________
4th Marking Period Chemistry Project - Attach This Patent Information Sheet to the patent that you hand in for your project. The project is due Tuesday, May 8, 2007
Patent Information Sheet

Student Name __________________

1. What is the name of the invention?

2. What is the Patent Number of the invention?

3. What is the name of the inventor? If the patent had been assigned to a company, what is the name of the company that “owns” the patent?

4. What is the date of the invention?

5. Summarize the claims, or specifications of the invention. Why did the inventor come up with this idea?

6. What did the inventor do to show that his invention actually works? (This is called reduction to practice.)

7. What resources did the inventor use to manufacture his product?

8. Summarize the history that led to the invention (prior art). What improvements did the inventor make, or why is the invention useful?

9. Is the invention an example of the saying “Necessity is the mother of invention?” Why, or why not?

Sunday, April 08, 2007

How To Make a Paper Model of DNA

How to Make a Paper Model of DNA

Modeling is a process used by scientists to assist in understanding the how the world works. Making models of molecules helps biologists and chemists define how the molecule is put together and predict the chemical nature of the molecule. James Watson and Francis Crick used modeling, along with the X-ray crystallographic images of Rosalind Franklin, to determine the structure and nature of the DNA molecule. I have devised a pattern that can be used to construct a paper model of the DNA molecule. This simple model helps students learn some(not all)of the properties of the construction of the molecule. In addition, the model shows off the beauty of the shape and symmetry of DNA. The patterns for the paper model can be obtained from my April 8 posts to this web site: http://www.cavalierscience.blogspot.com/

http://cavalierscience.blogspot.com/2007/04/how-to-make-paper-model-of-dna.html

http://cavalierscience.blogspot.com/2007/04/cut-out-pattern-for-making-paper-model_08.html
http://cavalierscience.blogspot.com/2007/04/cut-out-pattern-for-making-paper-model.html

There is a pattern for the 5 prime side and another pattern for the 3 prime side. You need to print and use both patterns to make the model.

First, the model illustrates that the DNA has two different, complementary sides. Second, the model shows that on one side, the sugar phosphate backbone of the molecule is bonded with the 5' end going to the 3' end, and the other side of the molecule is bonded with the 3' end going to the 5' end. Third, if students pay attention, when they are constructing the molecule, they will see that the Adenine base always pairs with the Thymine base and that the Cytosine base always pairs with the Guanine base.

Lastly, students get a feel for how the helical shape comes about; the molecule fits in such a way that it has a natural twist. And there is more. When everyone's model is made, the models can be taped together, end-to-end, to illustrate that DNA is a very long twisted molecule.

After the paper model patterns (see previous posts) are copied, they are cut out on all of the solid lines. The shaded areas in the pattern are discarded. The dotted lines allow for the bases to be folded to create the horizontal rungs of the DNA "ladder." Transparent tape is used to tape together the bases (hydrogen bonds). One base is placed slightly on top and overlapping the other matching base, and then the tape is applied by wrapping it around both front and back. Once one base pair has been put together, all of the other base pairs must be put together in the same way. If this is done properly, the molecule will naturally twist into a perfect double helix. This is somewhat realistic because it demonstrates that there are 10 base pairs per full turn, of the helix, which is what is found in the real DNA molecule. Copying the patterns onto colored paper adds interest and beauty to the model. Also, copying the pattern onto tag board, or manila folder, makes the model stiffer, as shown in the photos.