Download Mutations: Altering the Code

DNA: Codebreaking Worksheet
Date_________________
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Name________________
DNA Codebreaking
Summary
In this activity, you will translate a message into the
language that our cells use, which is the DNA code. You can
also use the DNA code to send secret messages to your
friends or family.
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Goals
 Understand how DNA encodes the directions to build
specific proteins
 “Read” the genetic code
Translate a message from English to the DNA code
Decode a DNA sequence into an English Message
Protein Synthesis Background information
Protein synthesis occurs in 2 main steps: Transcription
and Translation
Transcription: “copying DNA into RNA”
1) Transcription begins in the nucleus
2) The enzyme Helicase unzips a double stranded DNA
molecule
3) A complimetary mRNA strand is copied by RNA
polymerase adding nucleotides to on one side of the unzipped
DNA Strand. (Notice the base U (Uracil replaces T (Thymine)
4) mRNA Strand is sent out of cell nucleus into cell
cytoplasm. When it gets to a ribosome the process of
translation will begin.
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Translation: “Using mRNA and tRNA to make proteins”
5)
A ribosome engulfs the section of the mRNA
6) A tRNA molecule attaches to the
mRNA strand by matching bases
from its anticodon to mRNA’s codon.
This tRNA molecule is attached to an
Amino Acid on the other end.
5) More tRNA molecules continue to
attach to mRNA strand matching their
anticodons with the mRNA codons.
Amino acids will attach to one another
building a long protein molecule.
Decoding Activity (next page of this packet)
In this activity you will be transcribe a double stranded DNA molecule into mRNA
and then tRNA. You will use a codon wheel to determine which amino acids bond to the
mRNA codons (not DNA or tRNA anticodons) in the code.
Encoding Activity (On a separate page)
In this activity you will be able to create a sentence in English using DNA code.
Just as our cells are able to “read” DNA to make proteins, your peers are able to “read”
your DNA message to produce a sentence in English.
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DNA Decoding
Mr. Carter has created a message for you in DNA in the space below. See if you can
eventually translate it into English after going through the processes of transcription
and translation.
51 TCA GTG ATG GCT TTC CCC GTT TAT TTT CTC TGT AGC CCT TAT
GGG TTC GTG CGT ATA CAG CGT CTC TCT TCT ACA TTC ACT GCT
GAT TCT CTC GGT CCT AGC ACA TTA TCT CAT 31
Step 1: Transcription
For the DNA sequence above, write the sequence of messengerRNA
(mRNA) codons that is synthesized during transcription. Start at the 31 end
of the DNA molecule, this will be the 51 end of your mRNA molecule. Be
sure to separate the codons into triplets.
mRNA:
Step 2: Translation
Using your mRNA code wheel, start at the 51 end of the mRNA molecule above and find
the amino acid that each codon produces working your way to the 31 end. Write in the
word “stop” wherever a stop codon is produced.
Protein Molecule:
Write the message in English below. Add spaces and punctuation where you think it is
necessary.
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Message in English:
Now, write down your name on this sheet of paper and remove it from your packet.
My name ____________________________________
Write a SCHOOL APPROPRIATE secret message in the form of a double stranded DNA
sequence below. DO NOT translate this code into English or mRNA. Be sure to arrange
the nucleotides in groups of 3 so that it will be easy for someone to transcribe it in to
mRNA codons. Only your top strand should be the one that contains your encoded
message.
Example:
5I ATG
CGA
TTA
etc.
3I TAC
GCT
AAT
5I
3I
Turn in this piece of paper to Mr. Carter.
________________________________________________________________________
The following instructions apply to the person who will receive this code.
Staple this sheet to the back of your packet.
My name ____________________________________
Decode the DNA code above in to mRNA. Separate and number the codons.
Decode the mRNA codons above into the 1 letter amino acid code.
Write the message in English below. Add spaces and punctuation where you think it is
necessary.
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