Tactile DNA

View of four base pairs connected with phosphates on the outside and nucleotides on the inside. Connected nucleotides are "A" and "T", "G" and "C", "T" and "A", "C" and "G"

DNA model Assembly

About

A DNA molecule consists of 4 different nucleotides. Each nucleotide consists of 3 components. A phosphate group, deoxyribose sugar, and a nitrogenous base. The 4 different nitrogenous bases (Adenine, Thymine, Cytosine, and Guanine) allow for the variability found within DNA.


IN DNA the thymine always connects with the adenine and cytosine always pairs with guanine.

This is shown in our puzzle and we use different shapes to form the connection.


Parts

The Tactile DNA puzzle is a tool to teach visually impaired students the chemistry and structure of DNA. Our puzzle contains the 4 different nucleotides (A,T,C,G) a phosphate piece and Deoxyribose piece.

Adenine "A" nucleotide. Top rounded connector attached to a rectangular body + semicircle on the bottom.

Adenine

Thymine "T" nucleotide. Top rounded connector attached to a rectangular body + hollowed semicircle on the bottom.

Thymine

Guanine "G" nucleotide. Top rounded connector attached to a rectangular body + a hollowed out triangle on the bottom.

Guanine

Cytosine "C" nucleotide. Top rounded connector attached to a rectangular body + triangle on the bottom.

Cytosine

Phosphate connector. Looks like an upside down "V". There is a "P" on each leg and Braille "P" on the center top.

Phosphate

Deoxyribose puzzle piece is a pentagon shape with two angled connectors on the top left and right. There is a bottom round connector on the center bottom.

Deoxyribose

Print Settings:

  1. Layer Height: 0.20 mm

  2. Initial Layer Height: 0.20 mm

  3. Number of Walls: 2

  4. Number of Top Layers: 4

  5. Number of Bottom Layers: 4

  6. Infill: 25 %

  7. Supports: Everywhere, 75% angle

  8. Bed Adhesion: Raft

  9. Estimated Print Time: 50 minutes

  10. Print Weight: 9 grams

  11. Print Size (X,Y,Z): 71.9 x 4.2, 68.8 mm

  12. Enable Retraction: Yes

Download:

A Kit consists of the following parts:

Deoxyribose: 8 pieces

Phosphate: 8 pieces

Adenine: 2 pieces

Thymine: 2 pieces

Cytosine: 2 pieces

Guanine: 2 pieces

Instructions

  1. Take a deoxyribose piece (Pentagon) and a Phosphate piece (L shaped piece)

  2. Connect the Phosphate to the Deoxyribose piece on the groove labeled 3’ The phosphate should be facing out and all of the letters should face the same direction

  3. Repeat the above steps 8 times

  4. Take a completed deoxyribose-phosphate piece and connect a base pair to a round circular hole. There are 4 different times of base pairs creating 4 different types of nucleotides. Completed models are shown below

View of Deoxyribose connected to one phosphate on the left at 3 prime and Adenine.

Adenine Nucleotide

View of Deoxyribose connected to one phosphate on the left at 3 prime and Thymine

Thymine Nucleotide

View of Deoxyribose connected to one phosphate on the left at 3 prime and Cytosine

Cytosine Nucleotide

View of Deoxyribose connected to one phosphate on the left at 3 prime and Guanine

Guanine Nucleotide

5. Now you should have 8 different nucleotides. 2 adenine nucleotides, 2 guanine nucleotides, cytosine nucleotides, and 2 thymine nucleotides.

6. Take an adenine nucleotide and a cytosine nucleotide and connect the A and T piece

7. Take a cytosine nucleotide and a guanine nucleotide and connect the C and G piece

8. Repeat steps 6 and 7.

9. Connect the Phosphates to the 5’ spot of the next deoxyribose molecule


View of Adenine connecting perfectly with Thymine. Adenine's semi circle fits into Thymine's hollow space for a semi circle.

A-T Connection

View of Guanine fitting perfectly with Cytosine. Guanine's hollowed out triangle base connects with Cytosine's triangle shaped base.

C-G Connection

Activites

How many different chains of DNA can be created with 4 base pairs?

In order to calculate the possible combinations we use factorials (!). 4 factorial or 4! is 4 * 3 * 2 * 1 = 24. This means there are 24 different arrangements of 4 nucleotides. Create all 24 combinations!


Class wide / Grade wide / School wide Project

  • Each student has four base pairs and creates any combination of nucleotides they would like; A, T, C, G.

  • Each student places down their four base pairs and connects them (or a teacher because of Covid) to each other. 20 students is 80 base pairs! 100 students is 400 base pairs.

  • Connect over many tables or attach along a hallway wall.

  • Explore how only four letters can produce an enormous amount of genetic information.

  • How long is a real DNA strand?