Nucleic Acid Structure and Function : Working with Models (Day 2 of 5)

This is a five day lesson series exploring the structure and function of DNA that I have been developing with my research partners at West Ed over the past three years.  By using multiple DNA models, this series gives students the opportunity for deeper exploration and discussion about the components and function of DNA as well as a chance to analyze the diverse ways each model reveals different pieces of information about DNA.  

On Day 1, we explore students' prior knowledge about DNA structure and examine paper models of DNA.  Standards: W.9-10.1, SL.9-10.1, SL.9-10.1d, RST.9-10.1, RST.9-10.4, SP2, SP7, SP8, XC-SF-HS-2

On Day 2, we utilize 3D models of DNA for comparison and deeper discussion.  Standards:  W.9-10.1, SL.9-10.1, SL.9-10.1d, RST.9-10.1, RST.9-10.4, SP2, SP7, SP8, XC-SF-HS-2

On Day 3 and Day 4, we delve into the process and scientific vocabulary of DNA replication using both paper and 3D models.  Standards:  W.9-10.1, SL.9-10.1, SL.9-10.1d, RST.9-10.1, RST.9-10.4, SP2, SP7, SP8, XC-SF-HS-2

on Day 5, we utilize puzzle piece models to compare and contrast DNA and RNA for greater depth of understanding and in preparation of for our next series of lessons on protein synthesis.  Standards:  W.9-10.1, SL.9-10.1, SL.9-10.1d, RST.9-10.1, RST.9-10.4, SP2, SP7, SP8, XC-P-HS-1, XC-SF-HS-2

I am using the models I have on hand:  a classroom model found on any science education supply website, paper models that you can build for students to use or have them build on their own, puzzle piece models I found in a closet in my classroom, and a special set of 3D printer constructed models of DNA created by researchers at Scripps Research Institute in San Diego, CA and brought to my classroom through West Ed, a nonprofit research and development agency that is also over seeing the Smarter Balanced educational testing system in many states now embracing the CCSS.  You can use any models you have on hand or others that you are able to get on loan through nearby university partners.  

My students were very happy with this lesson series and especially the amount of information they were able to understand and discuss through the focused use of these models.  I can't wait to hear about the models you choose to use and how the lesson works for you and your kids! 

Check out a personal note one of my students wrote to me about our time with the DNA models and what she learned from the experience.  I was so excited to see a student who didn't always feel successful in our class feel completely confident about her knowledge and to hear her contribute in both small and large discussions and activities through this lesson series using these amazing models.  

My deepest appreciation to the staff at West Ed including Jodi Davenport, Matt Silberglitt, and Jacqueline Powers along with the generous project funders of the 3D DNA models used in these lessons.  

• This material is based upon work supported by the National Science Foundation under grant DRL-1108896 and by the Institute of Education Sciences, U.S. Department of Education, under grant R305A120047. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation, the Institute of Education Sciences, or the U.S. Department of Education.
• For more information about the models, check out the website West Ed set up just for this project! 

1.  Ask students to take out their DNA paper model document from yesterday's work with the DNA paper model.  

2.  Refer back to the structure of DNA board work on the front board.

3.  Tell students that today we will be working with a different kind of DNA model, one that is 3D and is called a space filling model, which help us understand the structure and function of DNA a bit better.

4.  Ask students to move to their lab tables.

1.  Tell students that each of them will find a copy of the paper model they used yesterday along with an additional DNA model for each student pair at their lab tables.  

2.  Pass out the 3D model document and tell students that they will be using the same process as they did yesterday to connect the DNA terminology from the class list we created to the model.  

3.  Remind students that the focus today is on exploring the model and understanding its parts and that the writing it not the emphasis for now!  

• Note:  I find that saying this helps kids to focus on their conversations about and handling of the models rather than filling out their homework paper.  I reassure them that I will give more time and assistance for writing throughout our lesson series.

4.  As students are working, go around to listen in and discuss potential hints for them when they are stuck such as:  

What is the general shape of a sugar?  

How many carbons make up a pentose sugar?  

What do all bases contain?

I find that this base pairs green board image assists them as they determine the make up of bases (purines vs. pyrimidines) and I often use it as I go from group to group.

 5. Check out my students working with our models!  They were engaged, focused, and curious throughout our time working together on this lesson series.

Student working with DNA West Ed model part one

Students working with DNA West Ed model part two

Students working with DNA West Ed model part three

6.  As I look through the student work sample I can see that issues around identifying the individual bases have been resolved for students.  I can then remind them to go back to their work from yesterday using the paper model and fill in that information now that they have had additional practice with, exposure to, and support for the process of differentiating between the individual purines and pyrimidines.

1. Using the spokesperson protocol, ask students to look at the board list of DNA vocabulary and pick out the one word they would like to spend more time on together.

2.  When they have picked their word, ask them to have their spokesperson come up and put a check mark by it for all of us to see.

3. With the time remaining, discuss the words (typically, they will be purine/pyrimidine or covalent/hydrogen bonds) and check for understanding.   The base pairs green board image I use helps immensely at this point because students are sitting with their groups and handling their models while we talk.

 Now on to Day 3!