Download From DNA to Protein synthesis lab

Gurded lnquiry
choprer t 3
Lob Fream
What are the steps involved in making
a
protein?
EmFnaduefiesr
Before a protein can be buiit, the biochemical blueprints for its
construction must be packaged and transferred out of the DNA
"library." First, the specific sequence of DNA that codes for the protein is
transcribed into a complementary strand of mRNA. In eukaryotic cells, the
mRNA then leaves the nucleus and enters the cl.toplasm. In all cells,
the mRNA molecule attaches to a ribosome, where IRNA anticodons
translate the mRNA into amino acids. The completed amino acid chain,
or polypeptide, then folds into its final shape as a protein.
In this iab, you will model transcription of DNA and translation of
mRNA while you,decode secret messages.
SkEEls Foee*s
Use Models, Sequence
Fre-Leb QuesFE*ms
2.
briefly the process you wili use to decode the
eompore and eontuosf What role do stop codons play in protein
synthesis? What are they used for in the coded messages?
3. Fredict Which six letters will not appear in the coded messages? Give
a reason for your answer.
Lob
Skills lob
#n*A ffo Pre$eHm Sym*hesEs
FrebEesm
1. Sequence Describe
messages.
.
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Dote
Fr*<*dasr*
Fsr* &: How to Deeode
fotesseges
]..WritethecomplementaryrnRNAstrandfortheDNAsequenceglvei-r
each DNA triplet,
below by finding the mRi\A codoa that matches
started for vou. Finish the
base for base. The rRNA strand has been
transcriPtion.
CGA ATG
DNA; TAC CGT TTT CTT ATT TAC ATA ACT CTG
*RNA: AUG GCA AAA GAA UAA
mRNA codon from Step 1 with its
"stop" codon'
.orresionding amino acid' When the codon is a
,.stop; in the sequence. The amino acid sequence has been
include
started for you. Finish the translation'
2. Use Figure 1 to match each
methionine,ai@
I
MoP of mRNA
codons to omino ocids
Figure
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xc/
o !i
UI
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L=/
u4/a
.s
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Doie
3. Use the table to {i{id the singleJetter spnbol for each amino acid in
the sequence from Step 2. The syrnbois will spell out a sentence or a
familiar saying. The first word has been done for you.
iv{AKE
Symbol
Amino Acid
Symbol
Amino Acid
I
Alonine
A
Leucine
Arginine
R
Lysine
K
Asporogine
N
Methionine
M
,A,sportic Acid
D
Phenylolonine
F
Cysteine
C
Proline
P
Glutomic Acid
E
Serine
S
Glutomine
a
Threonine
T
Glycine
G
Tryptophon
Histodine
H
Tyrosine
t
lsoleucine
I
Perf B: Eeeoding
L
Voline
Messoges
from Part A to decode the following messages.
Remember to transcribe the DNA messages into mRNA codons and
then translate the codons into amino acids.
O. TGA CGA TTT CTC ACT ACA CGC GCG CTT
4. Use the procedure
b. CTE CTT ATT TAA AGC ATC CGT ATT AGT GGC ATA
e. TAC CTC CTT TGA ATT TAC CTT ACT CGT TGT ATT A,{A
TAT CAG CTC
d. TCT GTA CTT ACT GGG GAT CGC TTG ATT GTA CGG
AGC ATC ACG GTG CGA TTG CCC CTT CTG
e. TGT GTG CTC ACT AGA GTA TAG GGA ATT AGG CGG
TAT GAC AGC ATC CGA TGC ACT CTG CGC ACqTTA
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R.ese'ved
&az*Eyee *ae# €*ee<B*s#*
-i.'"*pph fgYBEp$s *o{,y did you know which bases io use when you transcribed
the
DNA sequence to mRNA codons?
DNA sequence for the tirst message in Part B began with
why or why not?
TGT CcAinstead of TGA CGA. Would the message change?
2. Prediet Suppose the
acids?
Anclegies Suppose some codons mapped to two different amino
What would the
What would the efiect be on your translation of coded messages?
effect be on the production of proteins?
3. Use
4. Sequence During the actual production of proteins
to a strand of RNA before it leaves the nucleus?
in a cell, what might happen
DNA to
ond Revise What step could you add after you t,un,t'ibe the
make a more complete modei of protein synthesis?
5. Evaiuote
ENBemd
Y*wr
EmquEc"Y
messages with
create your own secret message using DNA triplets. Exchange
that there is no
clursrrrut.s and try to solve the messages you receive. Remember
to come up
triplet for the letters B, I, O, U, X, and Z.Yoswill need to be creative
i^'iih messages that don't use those letters'
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