Lesson 2 - DNA Structure and Replication

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LEGO® DNA DNA Structure & Replication

With slides fromLEGO DNA/RNA Booklet 1

© The LEGO Group and MIT All rights reservedKV Version 4-22-11

LEGO Lesson 2 PPT DNA

Kathy Vandiver, Ph.D. and Amanda Gruhl, Ph.D. Community Outreach and Education Program, Center for Environmental Health Sciences (CEHS),

MIT, Cambridge MA

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DNA what else do they call it?

© The LEGO Group and MIT All rights reservedKV Version 4-22-11

Demonstrate the structure of DNA with teacher LEGO Model

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DNA what else do they call it?

A double helix…. Why?

© The LEGO Group and MIT All rights reservedKV Version 4-22-11

Demonstrate the structure of DNA with teacher LEGO Model

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DNA what do they call it? 1) Look at the LEGO model

See the twist/ spiral? that is a “helix”

See the 2 strands? See why DNA is called “the double helix?”

2) See how the 2 strands look like backbones? “Sugar + phosphate” LEGO = backbones 3) See any repeating parts? Nucleotides These small molecules are found in the nucleus. “Nucleotides are in the nucleus”. Easy to remember!

© The LEGO Group and MIT All rights reservedKV Version 4-22-11

Demonstrate the structure of DNA with teacher LEGO Model

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DNA opens up in the middle!

© The LEGO Group and MIT All rights reservedKV Version 4-22-11

Demonstrate the structure of DNA with teacher LEGO Model

Demonstrate how DNA can unzip!

REASON– The nucleotides are held together in the middle by very weak bonds.

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Remember about the nucleus. It has lots of free nucleotides + DNA

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Look at kit compartments/ see labels. Learn about DNA & RNA nucleotides

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What makes a nucleotide? Base, sugar, phosphate

Each person can do this activity. Do this page and continue on page 7

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What makes a nucleotide? Base, sugar, phosphate

Which two are bigger?

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Discover which DNA bases work together to make the DNA ladder

Each person can do this activity. Do this page and continue on page 7

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Early scientists were puzzled by Chargaff’s rules #A=#T and #C= #G

Each person can do this activity. Count your A, T, C, Gs A = ? C= ? T = ? G= ?

Chargaff’s rules: A=T and C= G

Did it work? Why must they be equal ?

© The LEGO Group and MIT All rights reserved

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Practice opening up the DNA. When does the cell open the DNA ?

Each person can do this activity.

Review: DNA is like a street –it has strands running in 2 opposite directions. DNA always pairs a big and a small nucleotide together.

© The LEGO Group and MIT All rights reserved

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Model the vocabulary words: DNA Gene and Chromosome

4 Students join their DNA sections (genes) together into one chromosome.

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DNA Replication! The cell will become two cells soon. Needs to copy the DNA

Put away nucleotides. Each team builds the DNA below. Continue pages 10, 11, 12

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Continue Replicating the DNA pages 10, 11, 12

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Continue Replicating the DNA pages 10, 11, 12

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DNA Replication is complete ! Look at the results. Are both the same? Where did the original DNA go?

DNA Replication! Check out what happened.

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DNA Replication Lesson Completed. Next slides are about DNA codons.

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Three nucleotides in a row means a certain amino acid.

Use the gene strips to help you learn about codons.

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Three nucleotides in a line means a certain amino acid.

Build with the gene strips

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Three nucleotides means a amino acid. Decode the protein message here !

Look up the DNA codons on page 16 & 17. Place the cards under the codon

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