Biology with Junk: Protein Synthesis and Words
Teacher Prep
Purpose: To help students understand the role of DNA, mRNA, tRNA and amino acids in the role
of protein synthesis. This activity will also introduce the concept of mutations.
Introduction: This activity is aimed at helping students understand protein synthesis with words.
The teacher’s desk will be the nucleus. The nucleus will have DNA strands. The mRNA molecule ( a
student) will get a copy of a DNA template and must transcribe the molecule at the teacher’s desk
(the DNA never leaves the nucleus).
The student will now go to his/her desk (the ribosome). The ribosomal student will translate the
mRNA code. The tRNA anti-codons will be hanging up around the class. The student must find the
correct anti-codon, flip up the card and find the word under the card (the amino acid). This will
continue until the sentence is complete.
If students incorrectly transcribe the DNA strand or the mRNA strand, then a mutation will occur
and the sentence will not make any sense.
Note: Every DNA sequence begins with an initiator codon (ATG) which must be present in order
for the sentence to make sense, and each sequence ends with a stop codon (TAG) which also must
be present.
Materials:




20 DNA template cards: these will be kept on your desk at all times. After all, DNA cannot
leave the nucleus
64 Anti-codon cards: these will be taped to the wall around your room
Paper: to write down the mRNA strand and the tRNA molecules and the sentence
Pen/Pencil
Procedures for the Teacher:
1) Make up all the DNA template cards and the Anti-codon word cards.
2) Hang up the Anti-codon word cards, so the anti-codons are showing.
3) Show the student the cards and tell them what they are.
4) Tell the students that your desk is the nucleus and the DNA templates cannot leave the area.
5) A student (mRNA) is to pick up a DNA template card, write down the DNA template card
number, and transcribe it into mRNA.
6) With the mRNA sequence, s/he will go back to the group’s desk and the ribosomal student will
write out the tRNA anti-codon sequence.
7) As the ribosomal student works, the mRNA student will go back to the desk and repeat step 5
and continue the process.
8) The tRNA student will search out the correct anti-codon card and flip the card over revealing
the word. S/he will write down the word.
9) After completing the sentence, a student in the group will tell you his/her group sentence. If
not correct, have the group go over the same DNA template. If correct, have the students pick
another card.
Note: Students may work together or in pairs (it is better to assign one student to be the mRNA,
another student will write down the anti-codon (ribosome) and the third student will search out
the proper words). Every sentence must have a start and stop.
Results and Conclusion:
The keys for the sentences, the tRNA anti-codon word cards, and the DNA fragments are listed
below.
20 Sentences:
1) Your mother wears a rubber band.
2) Your mother dresses you funny.
3) We have dog breath.
4) The Beatles are the best rock band.
5) An old rubber band breaks when pulled.
6) Biology is the best subject.
7) Drink water every day.
8) I love rock and roll music.
9) We are all demented puppies.
10) Biology is so much fun.
11) Education is the door to the future.
12) Your father wears a dress.
13) Your brother wears nothing.
14) We are all in this together.
15) We must be informed every day.
16) Rock and roll music is the best.
17) Biology is all around you.
18) Read a little every day.
19) DNA is the code of life.
20) DNA must be read for life.
tRNA Card with Words (that go on the back):
UAG = Stop (period)
AUG = Initiator (Start)
AAA = Your
AAC = mother
ACG = funny
ACA = breath
AGU = Beatles
AUC = band
CAC = rubber
CCA = when
CUC = love
GAA = all
GAU = and
GCG = fun
GGC = to
GUA = a
GUU = nothing
UAU = this
UCG = be
UGC = you
UUA = DNA
UUU = life
CCG = is
CCU = subject
CGA = drink
AAG = wears
ACC = have
AGA = the
AGC = best
AUU = an
CAG = breaks
CCC = Biology
CUG = roll
GAC = demented
GCA = so
GCU = education
GGG = future
GUC = dress
UAA = we
UCA = together
UCU = informed
UGG = read
UUC = code
CGC = water
CGG = every
CGU = day
AAU = dresses
ACU = dog
AGG = are
AUA = rock
CAA = old
CAU = pulled
CUA = I
CUU = music
GAG = puppies
GCC = much
GGA = door
GGU = father
GUG = brother
UAC = in
UCC = must
UGA = around
UGU = little
UUG = for
DNA Fragments (that go on cards):
1) ATGAAAAACAAGGTACACATCTAG
2) ATGAAAAACAATTGCACGTAG
3) ATGTAAACCACTACATAG
4) ATGAGAAGTAGGAGAAGCATAATCTAG
5) ATGATTCAACACATCCAGCCACATTAG
6) ATGCCCCCGAGAAGCCCTTAG
7) ATGCGACGCCGGCGTTAG
8) ATGCTACTCATAGATCTGCTTTAG
9) ATGTAAAGGGAAGACGAGTAG
10) ATGGCTCCGAGAGGAGGCAGAGGGTAG
11) ATGGCTCCGAGAGGAGGCAGAGGGTAG
12) ATGAAAGGTAAGGTAGTCTAG
13) ATGAAAGTGAAGGTTTAG
14) ATGTAAAGGGAATACTATTCATAG
15) ATGTAATCCTCGTCTCGGCGTTAG
16)
17)
18)
19)
20)
ATGATAGATCTGCTTCCGAGAAGCTAG
ATGCCCCCGGAATGATGCTAG
ATGTGGGTATGTCGGCGTTAG
ATGTTACCGAGATTCTTGTTTTAG
ATGTTATCCTCGTGGTTGTTTTAG