DNA Models for Non-Majors (and Majors!)

 

Tested Studies in Laboratory Teaching, 2015, Volume 36

Robert B. Ketcham

Abstract

Students build a model of DNA that is quite realistic in terms of the positioning of individual atoms. We refer to this as the big DNA model; it is the DNA Discovery Kit from 3D Molecular Designs. Student groups start with models of phosphate, deoxyribose, and two nitrogenous bases to assemble one nucleotide base pair. Then they assemble a sequence of 12 of these nucleotide pairs and study the molecular features that emerge. They copy the sequence of their big DNA model into a single strand Pop Bead model and lengthen it to 36 bases by adding randomly chosen bases. They compare the Pop Bead sequences produced by different groups. Then, assuming these nucleotide sequences are part of a gene, they convert them into amino acid sequences and consider how expectations differ when protein sequences reflect common ancestry rather than random generation. Several Group Activity Sheets drive the lab activity and the learning.

Keywords:  DNA, DNA model, molecular model

University of Oregon (2014)