In this article, we are going to outline a straightforward solution for making a DNA model. For this method, the nuts and bolts are:
- licorice sticks
- colored gumdrops
DNA, the source of genetic information in the human body is such an important part of a cell that understanding how it functions is a must for every biology student. And what could be a better way of understanding its dynamics than to build a DNA model that illustrates the key aspects?
Building a DNA model does not necessarily mean that you have to work from the scratch. While you can do so if you wish to, making use of some stuff that is readily available at home, but there are commercial kits that make the job much easier, entertaining, and more useful from the learning point of view.
No matter how you decide to build your DNA model, there are certain characteristics that your model must display and there are a few questions that you must answer yourself before laying out the foundations of your DNA model.
The first thing you have to make sure that your DNA model complies with is the double helix structure of DNA. Each of these helices will basically have a spine running from the beginning to the end. Sugar, phosphate, and nucleotide bases will all be added to this spine or backbone. Your DNA model needs to have two of these backbones, which also form the two strands of DNA, and make sure that these strands run anti-parallel to each other.
This anti-parallel running of the two DNA strands results in the presence of major and minor grooves. Major groove occurs where the two backbones are distanced apart while the minor groove is located at the point where they are closer to each other. It is important for your DNA model to depict these grooves because interaction with the bases gets easier on the major groove side as then the backbones are not impeding.
The DNA has a flexible helix, which means there are curves and bends in its structure owing not only to thermal activity but the pressure from binding proteins too. Do not turn your DNA model into a plain linear model.
A very important aspect of any DNA model is the base pairing part. Your model must have one of the nucleotide bases attached to the sugar-phosphate bond. Also, the nucleotide bases must be paired in the right combination, i.e. Adenine with Thymine and Guanine with Cytosine.
Steps of Making the DNA Model:
Step 1 – Lay all of the required materials on a plain table. You must have the gumdrops available in four different colors to represent the four nitrogen bases in DNA, i.e. Adenine, Thymine, Guanine, and Cytosine. Make four groups of colored gumdrops based on their different colors.
Step 2 – Make a note on the paper of which color represents which one of the nitrogen bases. This will be extremely useful when we start building the consecutive rungs of our ladder.
Step 3 – Placing the licorice sticks in an upright position forms the sides of the ladder in our DNA model. These licorice sticks also illustrate the presence of sugar and phosphate bonds.
Step 4 – Insert two-colored gumdrops in a toothpick considering the right combination in which these bases pair up. According to James Watson and Francis Crick’s DNA model, these bases are always present in DNA molecule in such that the quantity of Adenine always equals the quantity of Thymine while the quantity of Guanine is always equal to that of Cytosine. That’s because Adenine always pairs up with Thymine while Guanine with Cytosine.
Step 5 – Attach this toothpick to a licorice stick in a fashion that it forms the rung part of our upright ladder with the attached rungs model. One toothpick holds one pair of nitrogen bases.
Step 6 – Following the same method as above, build another strand of DNA that has a complementary pair of nitrogen bases. Your color table to match gumdrops against nitrogen bases will come in very handy now.
Step 7 – Both of these strands form dual-stranded DNA. It’s now time to build more rungs and fill them up with any sequence of right pairs of nitrogen bases.
Step 8 – In order to get the effect of a double helix, all you need to do is slightly twisting the uprights of the ladder counterclockwise.
You have now made a simple DNA model successfully. There are a lot of other factors to consider before you finalize your DNA model, but the basic ones have been covered in this article.