DNA, Replication and Transcription
Robert Jesberg
FETC Conference
Orlando, FL
January 28 – 31, 2014
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Workshop Agenda
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Looking at DNA and Forensics
The DNA, Replication and Transcription Set
DNA Ladder
The Double Helix and Replication
Transcription, Translation and Mutation
Forensics Challenge
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The DNA, Replication and Transcription Set
• 521 K’NEX Pieces
• Builds 19 color-coded models
• Supports a team of 2-3 students
• Models DNA and mRNA
• Models can be in the form of
ladders, on stands or with a
flexible central core.
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The Teacher Guide
• DNA Structure
– Building the DNA Ladder
– Forming the Double Helix
Structure
• Replication and Transcription
– The Basic Replication Process
– mRNA Production
• Coding, Translation, and
Mutations
– Coding Glucagon: A Small Protein
– Translation of a mRNA Transcript
– DNA Mutations
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Key Concepts
• Molecular Basis of Heredity
• Transcription and mRNA Production
• Chemistry of DNA
• Translation of the DNA Code
• DNA Structure
• Deletion, Substitution, and Insertion
• The Double Helix
• Enzymatic Control of DNA
Processes
Mutations
• Nuclear and Cytoplasmic Processes of
DNA
• Semi Conservative Replication of
DNA
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NSES Science Content Standards
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Unifying Concepts and Processes
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Evidence, models and explanation
Science as Inquiry
- Abilities necessary to do scientific inquiry
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Understanding about scientific inquiry
Life Science
Grade 5-8
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Grade 9-12
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Structure and function of living systems
- Molecular basis of heredity
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Reproduction and heredity
- Biological evolution
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Diversity and adaptations of organisms
Science and Technology
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Understanding about science and technology
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Next Generation Science Standards
• Develop and use a model to describe why structural changes to genes
(mutations) located on chromosomes may affect proteins and may result
in harmful, beneficial, or neutral effects to the structure and function of
the organism.
• Construct an explanation based on evidence for how the structure of DNA
determines the structure of proteins which carry out the essential
functions of life through systems of specialized cells.
• Ask questions to clarify relationships about the role of DNA and
chromosomes in coding the instructions for characteristic traits passed
from parents to offspring.
• Make and defend a claim based on evidence that inheritable genetic
variations may result from: (1) new genetic combinations through meiosis,
(2) viable errors occurring during replication, and/or (3) mutations caused
by environmental factors.
Building the DNA Ladder
• Refer to pages 2 - 3 in the Instructions Booklet.
• Each of the pieces in the set is color-coded to represent the various
chemical components of DNA.
• Turn to pages 4 – 5 to construct a DNA ladder.
• The chart at the bottom of the page indicates the nucleotides you will
need for this activity.
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Twisting the DNA Ladder to form a
Helical Molecule!
• Your challenge is to twist the ladder to form a
double helix and mount it on a display stand.
Refer to pages 6 and 7 in your instruction booklet.
• Keep in mind that DNA is a right-handed molecule.
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Replicating DNA
• The replication process provides the cell
with two exact copies of an original DNA
molecule.
• The original DNA is the parent molecule
and the newly formed DNA are the
daughter molecules.
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Transcription
• The model of mRNA shown on the
left carries the code from a DNA
template strand.
• If you refer to pages 18 and 19 of
the instruction booklet, you will see
how the model is formed and the
code transcribed.
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Translation and Mutations
• You can place the mRNA transcripts on large sheets of paper to translate the
mRNA.
– You can bracket the codons and use a key from the Teacher Guide to
determine the appropriate amino acid sequence.
• Mutation activities in the teacher guide demonstrate how the amino acid
sequence changes when an insertion, deletion, or substitution mutation
occurs.
– Each of these mutation scenarios can be modeled with the materials in
the DNA, Replication and Transcription Set.
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DNA and Forensics
• “CSI” type television programs have certainly brought crime scene forensics
and DNA fingerprinting into vogue with students! How do we tap that
growing interest to help students better understand the science behind the
TV screen?
• DNA models that can be coded to any nucleotide sequence can provide
endless opportunities for teachers to simulate molecular level crime scene
investigations and provide materials for further investigation of DNA and
mRNA.
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Let’s get down to work!
• Each group has been provided with a DNA sample from a crime suspect.
• Our first task is to list the sequence of nucleotides found on your molecules.
Refer to page three in your Instruction Booklet to determine the color codes
used for the various nucleotides.
• There are two standard conventions we can use to transfer the sequence to
paper.
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Representing Your Molecule on Paper!
- GCCAGATCATTT
CGGTCTAGTAAA –
-OR5’ GCCAGATCATTT 3’
3’ CGGTCTAGTAAA 5’
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Finding your Molecule
• I am going to collect all of the DNA molecules and place them on the floor.
• Your task is to review the molecules on the floor and determine which one is
yours.
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Forensics Challenge
• Follow the directions given and see if your group can identify the subject.
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Forensics Activity Summary
• Participants had to use a variety of science skills to identify the DNA match.
- Observation
- Analysis
- Record keeping
- Data collection
- Critical thinking
- Logical thinking
• The activity can serve as a spring board to further research related to DNA
fingerprinting, crime scene science, polymerase chain reaction, and forensic
investigational techniques.
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