TRANSCRIPTION
BELLWORK
OBJ: SIMULATE THE PROCESS OF TRANSCRIPTION
HW: FINISH TRANSCRIPTION PROBLEMS
1.
What is the “central dogma or big idea” of
biology?
2.
What are the 3 kinds of RNA?
3.
Describe the function of each type of RNA
4.
Give at least 2 reasons why making proteins
is such an important process
5.
When you are finished, write down as many
things as you can remember about the
similarities & differences between DNA &
RNA
VIDEO CLIP: CHEFS

http://www.youtube.com/watch?v=H5udFjWDM3
E
SO HOW DOES RNA MAKE PROTEINS???
DNA
RNA’s
function
is to
make
proteins!
DNA stores
information
to run cell
RNA
Protein
Proteins
actually
DO the
work in
the cell
PROTEIN SYNTHESIS


To get from a DNA gene to a protein, the cell has to
perform protein synthesis.
It requires 3 types of RNA:
mRNA
 rRNA
 tRNA


It happens in 2 parts:
Transcription
 Translation

TRANSCRIPTION
Transcription is the process of
making an mRNA copy of the
DNA instructions (recipe for a
protein). Occurs in the nucleus.
TRANSCRIPTION VIDEO CLIP

http://www.dnalc.org/resources/3d/Transcription
Basic_withFX.html
TRANSCRIPTION- STEP1
SIGNAL
Transcription begins
when the cell
receives a message to
make a certain
quantity of a specific
protein.
EXAMPLE

After drinking milk, your cells receive a signal to
begin making more LACTASE- the enzyme that
breaks down lactose (milk sugar)
What other
example can
you think of
that would
signal cells to
make a
protein?
TRANSCRIPTION- STEP 2
UNZIPPING
RNA Polymerase “unzips” the
DNA so it can get to the gene
(recipe for the protein) on a single
strand
What
kind of molecule is RNA
polymerase (hint- look at the ending of
the word)?
TRANSCRIPTION- STEP 3
BINDING & READING
RNA polymerase binds to the promoter or
starter DNA sequence (usually “TATA”) and
begins making the complementary mRNA
copy
PRACTICE

Try #1 on your transcription worksheet
G C C T G A C A C G T C A T C C C G A G T A A A
C
G _
A _
C _
U G_ U_ G_ C_ A_ G_ U_ A_ G_ G_ G_ C_ U_ C_ A_ U_ U_ U_
_ G
_ _

#2- Circle promoter (TATA)

GACCTATAGTCTAG
CTATAATGCTACACTGAGCTGCG

CAGGATATCAGATC
GATATTACGATGTGACTCGACGC

GTCGAACGTATACGGGTGCATGATCCT
GTATCGATCGAAATATCGATCGTTA

CAGCTTGCATATGCCCACGTACTAGGA
CATAGCTAGCTTTATAGCTAGCAAT


#3- Underline the sequence that will be copied into
mRNA
PRACTICE
Circle the promoter, underline the sequence to be made into
mRNA, make the complementary mRNA underneath

T G C A T A T G G G A T G T G C T G A T C G A T T G A G T G A

A C G T A T A C C C T A C A C G A C T A G C T A A C T C A C T
mRNA:
G G G A U G U G C U G A U C G A U U G A G U G A
TRANSCRIPTION- STEP 4
DNA CLOSES
After gene is transcribed, DNA zips
back up (closes)
TAKE YOUR HANDOUT

Fold it correctly to reveal the hidden picture!
TRANSCRIPTION- STEP 5
MRNA SPLICING
mRNA is spliced
 Segments called introns are removed (not part of
the recipe)
 Segments called exons are kept (final recipe)
TALK TO YOUR NEIGHBOR

How did the Harry Potter fold-in model the process
of mRNA splicing? Explain introns vs exons.
BELLWORK
1.
Explain the analogy of the cake making.
What is the Recipe book?
What is the copy of the recipe?
What is the recipe?
What is the ‘name’ of the recipe that alerts
you to it’s presence
What is the cook who ‘reads’ the recipe?
What are the ingredients called?
PRACTICE
Circle the promoter, underline the sequence to be made into
mRNA, make the complementary mRNA underneath

T G C A T A T G G G A T G T G C T G A T C G A T T G A G T G A

A C G T A T A C C C T A C A C G A C T A G C T A A C T C A C T
mRNA:
G G G A U G U G C T G A U C G A U U G A G U G A
Boxed-in parts = introns
Remove introns: G G G A U G U G C T G A
Mature mRNA:
A U U
G G G A U G U G C T G A A U U U G A
U G A
TRANSCRIPTION- STEP 6
MRNA LEAVES NUCLEUS
The mature mRNA leaves the
nucleus to find a ribosome
TRANSCRIPTION SUMMARY- SUMMARIZE
TRANSCRIPTION TO YOUR NEIGHBOR
TRANSCRIPTION ACTIVITY
1.
You and your partner will receive a “signal” in the cytoplasm (lab
table) to begin transcription of a specific protein
2.
Go into the nucleus (desk-side) & find the appropriate gene on the
DNA molecule to transcribe mRNA from
3.
Record the mRNA on your worksheet
4.
Splice the mRNA according to instructions
5.
Take your mature mRNA out of the nucleus & into the cytoplasm
to (double check it with the answer key at your lab table)
6.
Move to the next lab table to get a new signal & repeat
**If you finish early, begin the HW problems
CLOSURE
Write a note to a student who was absent explaining
what they need to know about transcription.
**If you finish early, begin the HW problems