DNA Model

$150.00

This DNA kit includes:

  • 40 orange phosphate groups (8 extras are included to help demonstrate bonding energetics)
  • 32 white deoxyribose (sugar) molecules
  • 8 each of the nucleotide bases guanine(G), thymine (T), adenine (A), and cytosine (C)
  • Assembly instructions
  • Replication instructions
  • Scale comparisons

Overview of The Features and Functions of DNA You Can Demonstrate Using The DNA-Only Model

It is our intention that in using this model you and your students will be able to demonstrate all the basic parts and functions of the central molecules of life – and learn about them in a different and memorable way. We model creators especially remember the time during the building of the model when we got the angles between the bases and the sugars just right, and – in a kind of WOW! moment – saw the model twist into a helix. We also found that playing with the model raised questions about cellular information and machinery that we had never asked before.


Here’s what your students can discover with this model:

1. DNA Parts

The four different chemical components of a DNA strand are called nucleotides.

Each nucleotide, in turn, is made of a phosphate molecule, a sugar molecule, and one of 4 different base molecules: adenine (A), thymine (T), guanine (G), and cytosine (C).

2. DNA Bonding

  1. Nucleotides are linked one to another in two different ways – by chemical bonds between their sugars and their phosphates creating a backbone, and by chemical bonds between paired bases, creating a helix.
  2. The pairing of the bases is specific: A will only pair with T and G will only pair with C.
  3. The bonds that hold the bases together are weak (hydrogen bonds).
  4. The bonds holding the backbone sugars and phosphates together are strong (covalent bonds). Thus, the backbone remains intact when the bonds between the paired bases are broken.
  5. Covalent bonding requires energy. Each nucleotide entering the DNA strand arrives with two additional phosphates bonded to its single phosphate. The energy residing in that bond of two phosphates is used to create the new bond between the phosphate of the entering nucleotide and the sugar of the nucleotide just preceding it. The two extra phosphates are discarded in the process.

3. DNA Chain Orientation and Helix Formation

DNA exists in nature as long oppositely oriented chains held together by bonds between their paired bases. (The phosphate end of the chain is called the 5 prime (5’) end, and the sugar end is called the 3 prime (3’) end. The model cannot be assembled properly if this property is ignored.

The angle between the plane of the bases and the sugar to which each base is attached (36°) causes the double chain to take the form of a double helix, with ten pairs of bases per single turn of the helix (360°).

4. DNA Replication

A double helix is accurately replicated when proteins (represented by your hands):

  • separate the two strands of a single DNA helix,
  • attach new DNA nucleotide bases to their complements on the “mother” strands,
  • and link the new DNA nucleotide sugar/phosphates one to another to form two new identical DNA molecules.

[video://youtu.be/Xqvz1ACB3Z4]

5. DNA as Information

The information for building proteins, cells, you, and every other living thing is encoded in DNA as sequences of nucleotides (Analogous to the sequences of letters in language, digits in programming and dots and dashes in Morse code.)

Over long periods of time, information is altered by mutations, which are changes in nucleotide sequences.

6. The Location in the Cell Where These Processes Occur

DNA replication takes place in the nucleus of cells that have a nucleus (eukaryotic cells),
And in the cytoplasm of cells that don’t (prokaryotic cells).

7. Genetic Mutation and Repair

Excision repair – when damaged, say by laser or radiation, a mutated nucleotide flips out, is removed and replaced by the correct nucleotide.

Non-excision repair –a mutated nucleotide flips out, is chemically modified and returns to bond with its complement.

8. Scale Dramatization

If the entire DNA in only one human cell were stretched out in one long strand it would be about 1 meter long. If the same amount were represented by the model and similarly stretched out, it would be about 93,000 miles long…

9. Genetic Chains are Looooong

The full length of human DNA is many millions of nucleotides long. The average gene is over one thousand nucleotides. A gene of that length would produce a protein over three hundred amino acids long. Some genes are more than three times that length. The model is designed to illustrate the principles, but obviously, it cannot convey the actual length of DNA molecules.


If you wish to go further and discover the forms and functions of RNA, tRNA and amino acids, and demonstrate not only DNA replication, but transcription and translation as well, contact TeachDNA at jhhauck@comcast.net.

The model has been a great success with my students. They love it! It really is the best I've seen.

The kids had already read about and made an origami model of the double helix before they saw your model. I linked half of the nucleotides together into a single chain while they told me the parts. Then I handed out the rest of the nucleotides to the class. As I went down the chain I called out a base students called out if they had the complement.  I went around the room and students 'hydrogen bonded' their nucleotides to my chain. After I had all the complements snapped on, I 'made like an enzyme' and knit the other backbone together. There was actually an intake of breath as they saw the helix taking shape.

Kate Fraser
Secondary Science teacher
Perkins School for the Blind

Read Full Review

The pictures were great; the instructions in general were incredibly helpful.  The understanding of the DNA structure and replication was deep and sufficient.  Students enjoyed manipulating the pieces and discovering how DNA could and could not be constructed.

Emily Flaherty
Westbrook, ME

Read Full Review

I teach two biology courses made up primarily of sophomores and juniors. I have students of all learning styles and abilities in these two classes. I choose to introduce this lesson after covering cell structure and function, and mitosis and meiosis. I had previously given notes on DNA, assigned reading from the “The Way Life Works”, constructed DNA from paper, and extracted DNA with my two classes. After having already completed much of my instruction related to DNA, I believed that introducing the model to my classes would serve primarily as a reinforcement activity. I was wrong. 

Shannon Cutts
Upper Valley Teacher Institute
NH

Read Full Review

The model has been a great success with my students. They love it! It really is the best I've seen.

The kids had already read about and made an origami model of the double helix before they saw your model. I linked half of the nucleotides together into a single chain while they told me the parts. Then I handed out the rest of the nucleotides to the class. As I went down the chain I called out a base students called out if they had the complement.  I went around the room and students 'hydrogen bonded' their nucleotides to my chain. After I had all the complements snapped on, I 'made like an enzyme' and knit the other backbone together. There was actually an intake of breath as they saw the helix taking shape.

On Friday afternoon we met with 4 biology students during their double period lab. The students used the models to review the concepts of DNA replication. The design of the model allowed the students to easily recognize the different types of bonding in the DNA molecule by the bonds’ varying strengths.  The students also tactually identified the macromolecules that comprise the DNA molecule by their unique shapes and locations.  The construction of the molecule allowed the students to use it to carry out all the DNA processes illustrated in high school biology texts. In addition, the models enable the students to lean the basics of the DNA code and to build sample codons. The learning activities possible with this model are the most varied and beneficial of any DNA model I have ever used.
By using this model the students were able to easily understand concepts that they had struggled to learn and that I had labored to teach them with our existing resources. Our students' comprehension of the principles of DNA will be evaluated by the MCAS testing. Also the information about DNA and genetics that sighted students can learn by looking at diagrams or computer generated modeling can only be conveyed to our students by effective models such as these. In addition, an understanding of DNA is essential in today's growing biotechnology industries.  Possibly models such as these could open up future careers for our students.

Thank you.

Kate Fraser
Secondary Science teacher
Perkins School for the Blind

The pictures were great; the instructions in general were incredibly helpful.  The understanding of the DNA structure and replication was deep and sufficient.  Students enjoyed manipulating the pieces and discovering how DNA could and could not be constructed.

Emily Flaherty
Westbrook, ME

I teach two biology courses made up primarily of sophomores and juniors. I have students of all learning styles and abilities in these two classes. I choose to introduce this lesson after covering cell structure and function, and mitosis and meiosis. I had previously given notes on DNA, assigned reading from the “The Way Life Works”, constructed DNA from paper, and extracted DNA with my two classes. After having already completed much of my instruction related to DNA, I believed that introducing the model to my classes would serve primarily as a reinforcement activity. I was wrong. 

The DNA model is three dimensional, and there is only one correct way for it to be assembled. Prior to this lesson, my class was could correctly represent DNA on paper, discuss how it is replicated, identify the parts of a DNA molecule and could describe how DNA is unzipped and replicated. I was amazed by how many of my students, when asked to physically construct a DNA molecule using the “realistic” model, initially struggled with the application of their knowledge. 

At first, many groups asked for more information from me. I directed my students to the materials they had before them, and assured them that they had all of the information they needed in order to complete the assignment. A change vibrated throughout the room as group by group began to correctly assemble the model. I heard many exclaim “oh now I get it…” and students encouraged their classmates to “try this…”, “pull on this…”, and “connect that…”. Many of the things I believed they had already learned about DNA were either newly discovered or reinforced as they progressed through the lesson. 

After this lesson we went on learn about protein synthesis and RNA. I pulled out the model to again reinforce what the students were learning, as well as to support my own instruction. It served as an excellent representation of part of this process as it allowed me to hold nucleotides before them and physically move them about during my explanation. 

I know that my class now clearly understands DNA. My students have also informed me that they definitely prefer the realistic model of DNA to the paper copy they had to label, color, and cut. They weren’t afraid to handle and manipulate the three dimensional model. It was durable to exploration, great for discovery, and far more beneficial in comparison to the paper representation most classes rely on. 

I highly recommend the book and model as an effective, educational, hands-on, and fun way to teach students about the structure and replication of DNA. These resources were an asset to my high school biology courses. 

Shannon Cutts
Upper Valley Teacher Institute
NH

AttachmentSize
PDF icon 1.modeling_a_molecule.pdf382.65 KB
PDF icon 2.atoms_to_info.pdf354.55 KB