Download DNA Starter Kit Information

...where molecules become real TM
DNA Starter Kit
©
Contents
1-Group Set Contents
12 Red Foam Adenine Bases (DNASK-R-A)
12 Blue Foam Cytosine Bases (DNASK-R-C)
12 Green Foam Guanine Bases (DNASK-R-G)
12 Yellow Foam Thymine Bases (DNASK-R-T)
3 White Foam Uracil Bases (DNASK-R-U)
48 Orange Phosphate Pieces (DNASK-R-P)
48 Orange Connector Pieces (DNASK-R-C)
4 Gray Foam DNA Backbone Pieces (DNASK-R-Backbone)
1 Bag with 24 Blue, 24 Yellow and 6 White Bands (DNASK-R-Bands)
24 Gray Sugar-Phosphate DNA Backbone Pieces (DNASK-R-GSP)
12 Purple Sugar-Phosphate RNA Backbone Pieces (DNASK-R-PSP)
Please contact us if any parts are missing or damaged.
Replacement Parts Available Order replacement parts with the item number in
parentheses from the above list in our catalog or online at www.3dmoleculardesigns.com.
DNA Backbone
Thymine
Adenine
Cytosine
Guanine
Uracil
Sugar-Phosphate
DNA Backbone
Sugar-Phosphate
RNA Backbone
Phosphate
Connector
!
WARNING:
CHOKING HAZARD -- This product contains small parts and
should be kept out of the reach of children under the age of 3,
because the parts or their pieces may present a choking hazard
to small children.
CAUTION:
This is a science education product,
not a toy. It is not intended for
children under 8 years old.
1050 North Market Street, Suite CC130A, Milwaukee, WI 53202
Phone 414-774-6562
Fax 414-774-3435
3dmoleculardesigns.com
...where molecules become real TM
Assembly
To complete your pyrimidine bases (blue cytosine, yellow
thymine & white uracil) you will attach the sticky-backed foam
bands to each side of the base as shown at left. (Please remove the
paper backing on the bands first.) The prongs of the
pyrimidine bases should be completely covered by the stickybacked bands. These sticky-backed bands provide stability for the
model and reduce confusion between base pairs.
Narrow
Wide
Match the shape of the band to the shape of the base.
Note the angle cut on the bands. Place the narrow end
at the outside of the prongs. See photo.
Note: If over time the bands on the pyrimidines become loose, or are not sticking to
the foam base, use super glue to re-attach them.
Powder Bases Before Using
The adhesive on the bands makes joining and separating the base
pairs difficult. This stickiness can be eliminated with talcum
powder. Dip the purines’ exposed prongs into
the talcum powder provided. Insert the purine
into the complementary pyrimidine. The bases
should easily attach and detach.
Care & Maintenance
The foam will tear if too much force is used. Encourage your students to be careful. Wash
with a damp cloth or, if necessary, a mild dishwashing detergent.
Misconception Caution
Models are powerful teaching tools, but can cause misconceptions.
With this DNA model, students might develop the misconception
that DNA is made by simply adding the four DNA bases (A,T,G,C)
to a pre-formed sugar-phosphate backbone. To avoid this
misconception, we encourage you to explain that a nucleotide
consists of a base, deoxyribose sugar and a phosphate group. You
can use the individual sugar phaosphate pieces joined to the base to help your students
visualize the individual nucleotides.
Individual nucleotide units are then joined together by phosphodiester bonds to build up
the alternating sugar-phosphate backbone of DNA as it is synthesized by DNA polymerase
enzymes in the cell.
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...where molecules become real TM
Introduction
DNA Starter Kit Pilot Study
©
Pilot Study
Thank you for purchasing the Pilot Study Version of the DNA Starter Kit © ! We value your
insights on how this kit may be used to help your students learn important concepts about
DNA. You will have two venues in which to share your input.
Share Your Comments & Lessons Online
The MSOE Center for BioMolecular Modeling is hosting an interactive website for the Pilot
Study. 3D Molecular Designs is posting photos and other resources. You will be able to post
your lesson plans, photos, comments, feedback and/or suggestions, and view materials
developed by other teachers. While posting is optional, we hope you will be willing to share
your ideas with us. http://cbm.msoe.edu/DNAStarterKit
Survey
Within a month of receiving the kit(s), you will receive an email with a link to a survey.
The first 100 people to complete the survey will receive replacement parts/kits for every kit
purchased.
DNA Structure
Build your DNA model with either the long continuous backbone, or the individual sugarphosphate pieces. Remember, the base always attaches to the sugar (deoxyribose or
ribose). Create half of your model by attaching 12 bases to the backbone. Then attach the
complementary bases to either the long backbone or individual pieces.
Note: Pull
the base
through the
DNA backbone hole
until flared ends pop
through. To remove
a base from the DNA
backbone, squeeze the
flared ends until they
fit through the hole.
To create the double helix, rotate the bases so that
they are vertical instead of horizontal, as shown
left.
With your right hand on the top base pair and
left on the bottom twist your hands in opposite
directions. (Your right hand should twist
counterclockwise and your left hand clockwise). Twist
until the DNA backbones touch each other in a tight coil.
Release the bases and allow the model
to relax into its double-helical shape.
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...where molecules become real TM
Using the DNA Starter Kit ©
Deoxyribonucleotide Triphosphates (dNTPs)
DNA (RNA) Synthesis*
We include deoxyribonucleotide triphosphates in the DNA Starter
Kit© to help students understand that during the process of DNA
replication (or RNA transcription) these nucleotide
triphosphates serve as the substrates (monomeric subunits) that
are joined together by DNA polymerase (or RNA polymerase) to
create the complementary strand of DNA (or RNA). A significant fraction of the cell’s
metabolism is devoted to maintaining an adequate supply of these nucleotide
triphosphates for DNA replication and/or RNA transcription. As the nucleotide
triphosphate is added to the growing chain, a high energy phosphate bond joining the
three phosphate groups together is cleaved by the polymerase – releasing a pyrophosphate
(PPi) and incorporating the nucleotide monophosphate into the growing chain.
Energy Metabolism*
As an added benefit, students can construct models
of ATP (adenosine 5’-triphosphate) as they consider
this “universal currency of cellular energy”. ATP is
generated by ATP synthase as it binds both ADP
(adenosine 5’-diphosphate) and Pi – and then forms
the final high energy phosphate bond to create ATP.
This key reaction in the cell is powered by the high
proton concentration that is built up in the inter-membrane space of the mitochondria, as
a result of oxidative respiration.
*Depending on the level of your students you may not use this information and/or the phosphate pieces.
Replication
5’
3’
Start with your DNA Starter Kit© model in its ladder shape and unzip the base pairs at one end of
the DNA. the two strands of complementary DNA
should be antiparallel. Begin by adding
complementary deoxyribonucleotide triphosphates
(dNTPs) to the 3’ end of the single-stranded DNA
(the end with the point of the arrow).
3’
5’
5’
3’
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...where molecules become real TM
Replication Continued
Each time another dNTP is added:
• break the phosphate bond between the first and second phosphate group
• set the resulting pyrophosphate aside (the orange PPi)
• form the phosphodiester bond to the previous nucleotide by slipping the hole in the
remaining phosphate over the peg in the deoxyribose.
Note that to replicate the opposite strand of DNA, you
would have to start at the replication fork – and join
complementary dNTPs together as you move along
the opposite strand – toward the unzipped end. In
this way, both replicated double-stranded DNAs will
be anti-parallel. This idea may be too sophisticated
3’
for younger students – who could simply replicate
one strand of the DNA in an anti-parallel manner –
and then replicate the opposite strand once it is
completely freed from the original double-stranded DNA.
5’
3’
5’
3’ 5’
3’
5’
Transcription
RNA can be transcribed from either of the two DNA strands in much the same way as DNA
was replicated. But rather than unzipping the DNA from one end, we suggest that you
create a transcription bubble by separating several base pairs in the middle of the DNA model.
And then as you begin transcribing one of the two strands of DNA – by adding
ribonucleotide triphosphates together, splitting off a pyrophosphate at each step – be sure
that the RNA strand that you are making is anti-parallel to the template strand of DNA.
5’
3’
3’
5’
3’
5’
You might also want to point out to students that only one of the two strands of a gene is
transcribed into mRNA. Transcription of the opposite strand would result in an RNA that
would encode an entirely different sequence of amino acids.
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