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 © 2004 ENSI (Evolution & the Nature of Science Institutes)
This material may be copied only for noncommercial classroom teaching purposes, and only if this source is clearly cited.


An Introduction to
DNA Structure,
Replication, and
Protein Synthesis

by Larry Flammer




Something Different: This DNA manipulative kit allows students to ultimately translate a DNA code-message by synthesizing a "protein" (amino acid sequence) in readable English, and encourages students to create and decipher new messages written in DNA language. Kit consists of 4 parts or stages: 1. Nucleotide Structure (in which simplified symbolic shapes are used to learn the basic structure of RNA and DNA nucleotides); 2. Replication; 3. Protein Synthesis; 4. "Say It With DNA" (or Protein Synthesis Practice Worksheet") for practice on longer messages.


The basic structure and function of DNA are fundamental to all biological processes.


1. Very few simple building blocks can be assembled in such a way that they can hold the complete set of instructions for making a living organism.

2. DNA bases match (pair) in specific ways: A with T, C with G, (A with U in RNA)

3. DNA makes RNA makes Protein ("The Central Dogma" of Protein Synthesis, as detailed above)

4. DNA is the central repository of information (in molecular code form) that controls life prcesses via protein synthesis.


   Students will....

1. recognize the basic substructure of DNA and RNA
2. recognize DNA as a central repository of information (in code form) which controls life via protein synthesis.
3. know the "Central Dogma": How DNA makes RNA makes Protein, in some detail.
4. know that certain DNA bases match: A & T, C & G, (and A & U in RNA)


TEACHER MATERIALS: (Click on each to download and printout)
DIY DNA.Tchr Intro
DIY DNA.Tchr.Setup.Inv
DIY DNA Demo Slides

Scissors, paste (or glue sticks), and envelopes


2-4 50 minute periods, depending on:
- whether the Nucleotide kit is done at home, or at school
- whether students have to cut out all pieces for each part, or use pre-cut kits
- how much class time is used for making and decoding messages
(12 PDF Files)
DIY DNA.Student Intro
DIY DNA.Study Plan-Obj
DIY DNA.1.1.Nucleotides
DIY DNA.2.1.Replication
DIY DNA.2.3.pdf
DIY DNA.3.1.Protein Synth
DIY DNA.3.3.




1. Download and print the Teacher Introduction and Teacher Setup and Inventory, and the Student Introduction. Read these..

2. The kit is best used in your introduction to DNA. Download and print the Student Study Plan / Objectives for one possible approach.

3. Download, print masters of the Student Handouts, and make sufficient copies for your students (see quantities and page colors in the Teacher Setup sheet). Plan to handout each of the 4 parts separately, not altogether.


1. ENGAGE: Have at least one model of DNA to show, and possibly some pictures to post on your bulletin board and/or to project on your screen. Engage your students by asking what they know or have heard about DNA (and record their responses on the board). When they seem to have exhausted their combined knowledge, present some of the current and likely future benefits of our knowledge of DNA, items that they probably did not mention. [Do some Google searching and/or reading beforehand to prepare yourself for this. If not satisfied with what you find, contact the webmaster.]

You may need to point out to them that people are being required more and more to understand various medical conditions that they mey develop, so they can work more effectively with their doctors to maintain or improve their health. Doctors can't do it all. So it's important for everyone to have at least a basic understanding of DNA and how it works.

2. With all that potential for DNA, and its central role in all of biology, not to mention its applications in medicine, agriculture, ecology, anthropology, computer technology and crime detection, build on that anticipation by pointing out that that this amazing and seemingly complicated molecule is basically very simple. They will easily teach themselves about its simple substructure and the simple rules for its sequential structure, and the easy-to-understand basic processes by which it works.

3. Hand out the Student Introduction and kit part 1; Nucleotides

4. Follow the suggested Study Plan, or your own variation.


Obviously, notice the degree of engagement and enthusiasm of your students (actually easier to spot those NOT engaged, who you can approach and offer some help and further encouragement).

Besides the obvious "factoid" questions on DNA (e.g., "What nucleotide base pairs with Thymine?"), be sure to develop good questions that assess the other Assessable Objectives (above), and the general significance of knowing and understanding the role of DNA in modern biology, medicine, agriculture, ecology, and forensics, and how it will affect all of our lives more and more.



1. Be sure to follow this lesson with the "Say It With DNA" lesson. It follows logically from their experience with the Do It Yourself DNA lesson.

2. When you want to show how DNA controls all the complexities of cell behavior (the "One Gene - One Enzyme" idea), show them at least the first part of our PowerPoint presentation on Pseudogenes (with script).

3. Students can use the DNA Message Maker to create the DNA sequence which would code for their initials or 3-letter name or nickname, then use that code to build DNA jewelry (earrings, etc.) in the Genetic Jewels activity. They would have to be sure that the base letters (beads) for the code runs end to end along one strand, and the complementary base letters (beads) run along the connected strand. Such items would have even greater meaning and be uniquely personal, contributing to their retention of understanding.

4. Modeling DNA: Students stand in two parallel columns, with adjacent fists out to side, touching neighber fists, thereby forming nucleotide pairs. They learn how to move to show replication and protein synthesis. See details in article in The Science Teacher for Summer 2016.

5. BIG DNA MODEL: As a special project, a student (or team) could build a large DNA demo model in which the base sequence codes for the name or initials of the school, or the school mascot. Flat rectangular sheets of styrofoam could serve as the base-pair steps; flat pentagonal pieces as deoxyribose sugars, and flat round pieces as the phosphate groups. See photo below. Here are the materials you will need:
Flat DNA model
G-C Template
A--T Template
D & P Templates
DNA Message-Maker

Big DNA Model


DNA/Genetics simulations, available from the CSH site:

DNA Workshop: You Try It (DNA interactive: Replication & Protein Synthesis: <>. Click on the DNA Workshop Activity (arrow)

Protein Synthesis Modeling: Alternative for studying protein synthesis, using larger scale paper cutouts, working in teams. This would work better if you did not do the complete Do-It-Yourself DNA kits


Some of the ideas in this lesson may have been adapted from earlier, unacknowledged sources without our knowledge. If the reader believes this to be the case, please let us know, and appropriate corrections will be made. Thanks.

1. Original Source: Larry Flammer, idea developed in 1963 and used in Biology classes ever since,

2. Edited / Adapted for website by L. Flammer 4/5/07


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