Students often struggle to understand the full implications of some basic chemical concepts of DNA structure and function, especially how DNA’s directionality and antiparallel nature determine key functional features of replication and molecular recombination. Visualizing the complexities of these processes requires a working knowledge of how DNA’s nucleotides are assembled and how these components interact. This article describes a simple activity that can be used to visualize how nucleotides join together, how base pairs form, and, most importantly, how the active processes of replication and recombination are related to DNA chemistry. In this activity, students model DNA structure, with each student representing a single nucleotide, then join together to form a polynucleotide with 5′ to 3′ directionality. Two chains then pair to form the antiparallel DNA duplex. The activity not only illustrates the basic chemistry of DNA but also allows students to participate in active modeling of leading-strand and lagging-strand replication and in the formation of the Holliday junction molecule, the basic intermediate of recombination events including crossing over and gene conversion. The demonstrations can be videotaped from above to make a permanent copy of these events for teaching and study purposes. Example illustrations and links to videos are included.
Skip Nav Destination
Article navigation
September 2021
Research Article|
September 01 2021
DNA in Motion: A Student Exercise for Modeling Key Molecular Events
David A. Johnson
David A. Johnson
DAVID A. JOHNSON is a Professor in the Department of Biological and Environmental Sciences, Samford University, Birmingham, AL 35229; email: djohnso2@samford.edu.
Search for other works by this author on:
The American Biology Teacher (2021) 83 (7): 458–463.
Citation
David A. Johnson; DNA in Motion: A Student Exercise for Modeling Key Molecular Events. The American Biology Teacher 1 September 2021; 83 (7): 458–463. doi: https://doi.org/10.1525/abt.2021.83.7.458
Download citation file:
Sign in
Don't already have an account? Register
Client Account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.