What is DNA? What is its purpose? DNA (deoxyribonucleic acid) is the basic unit of our physical and genetic makeup. It houses information expressed through our physical attributes, such as the color of our eyes, hair, skin, our height, etc. The design challenge presented here is to engineer DNA. In order to do this, students must first understand the basics of DNA. (Figure 1.) DNA is made up of two strands (refer to Figure 1) that are attached by base pairs. The structure of DNA looks like a spiral or coiled ladder. There are four bases: adenine (A), guanine (G), cytosine (C), and thymine (T). Amongst these base pairs, adenine (A) bonds to thymine (T), and guanine (G) bonds to cytosine (C). The bonding character between AT and GC differs in that A and T bonding consists of two long bonds and G and C has three shorter bonds.
[FIGURE 1 OMITTED]
The goal of this activity is to reconstruct DNA by investigating its structure and components. Students will be able to appreciate our genetic building blocks. Students will design, construct, and test various DNA structures. Using the engineering design process, students will be able to awaken their creativity and design ability towards understanding the genetic makeup of human beings.
The engineering challenge here is to design, create, and test engineered DNA. Students should focus their efforts and creativity towards understanding the interactions between the bond strengths, the coiling of the DNA, and the different base pair matchups of the DNA. Students will have to utilize their creativity, critical thinking, problem solving, and analytical skills when designing and constructing their own DNA. It is recommended that students do this activity individually.
Students should be encouraged to bring household items for constructing their DNA. Necessary items are as follows: wire-based materials that have the ability to bend and fold easily (pipe cleaners, wire hangers, copper wire, etc), glue, tape, Velcro, string, scissors--virtually anything that has adhesive or sticky properties. The adhesive material will serve as bonds. For constructing the base pairs, students should use their creativity and pick materials that are distinguishable in four different ways. For example, construction paper of four different colors, or different types of fabrics, rubber, and cardboard. Each student will need a cylindrical rod, no smaller than 0.5 inches in diameter.
Teachers should begin the design challenge with an open discussion with students by introducing DNA to the class. Describe the basic characteristics of DNA. Teachers should encourage students to question the properties of DNA and the role it plays in our lives. Once the foundation of DNA has been laid out, students should begin their design challenge: to engineer their own DNA. …