Materials: worksheet
*Turn in Central Dogma HW and Gizmo to Front
Tray by 2 min.
Catalyst (5 min):
1. What are the 3 processes included in the
Central Dogma?
2. What is happening in each process?
Elite Eight Trait Check-Up
1. Respect the Threshold
1. Everyone on time?
2. Silent for First Five?
2. Be Prepared (2 min)
1. Seated
2. Have materials
3. Working on catalyst
Announcements
• Need a binder by:
–Thursday: Periods 1, 2, 4, 6
–Friday: Periods 5, 7
• Know your Gizmo username and
password for Thursday/Friday
• Quiz over the Central Dogma on
Thursday/Friday
Objectives
• I can explain what is happening in
transcription and translation.
• I can explain the function of the 3
types of RNA.
• I can read a codon chart and create a
protein for a certain DNA strand.
THINK:
• What do you use your phone for?
• How can deaf people call to set up a doctors
appointment? (If you had to invent a
product/service for this to be possible, what
would you need?)
DNA
proteins
mRNA
transcription
translation
The Central Dogma of Biology!!!!
Dogma: a set of principles
Transcription
Where is DNA?
The nucleus
What is the end
product?
Proteins
What organelle
makes
proteins?
Ribosomes
(outside of the
nucleus)
Label the DNA and where the proteins
are made in the cell
DNA
Ribosomes:
make proteins
Why do we need RNA?
DNA needs to get ‘the
message’ out of the nucleus
It needs a messenger
Think/Pair/Share:
• Where does the
message need to go?
•What is the ‘message’?
mRNA (messenger RNA): carries information
from DNA to the ribosomes (in the
cytoplasm or on the Rough ER)
Transcription: making mRNA
from DNA
DNA
mRNA
Transcription happens in the nucleus
Steps during Transcription
• DNA unzips, exposing the strand that will code
for the message
• Free-floating nucleotides match up with the
appropriate exposed base creating a strand of
mRNA
– what protein do you think brings the mRNA
nucleotides to DNA?
• mRNA detaches and leaves the nucleus
• DNA zips back up
DNA: G C G T A T C G
mRNA: C G C A U A G C
Partner work (5 min):
Transcribe DNA Strands into mRNA strands
Answer one per pair on a half sheet of
paper.
1. ATCGAA
2. GGCATA
3. CTAGCG
4.What process did this represent?
5. What is being made and where?
Translation
Translation
Translation is the process of using mRNA
to build a protein.
mRNA
protein
Translation happens in the ribosome
Translation
Translation needs 3 types of RNA:
• mRNA (messenger RNA)
• rRNA (ribosomal RNA): makes up the
ribosome
• tRNA (transfer RNA): carries amino
acids (the monomer of proteins) to the
ribosome so they can make a protein
But HOW does mRNA code for
proteins?
PROTEINS are long strings of
Amino
acids
____________
The order of the amino acids
determines the shape of the
protein
mRNA uses a code to tell the
ribosome what proteins to
make
Codon: 3 letters of mRNA
together code for a specific
amino acid (there are 22!)
Think:
•
•
•
•
•
•
3 “letters” = 1 codon
How many codons would be in a strand of....
6?
2 codons (2 amino acids)
18?
codons!(6 amino acids)
6 codons
450????? 150
Proteins are often HUNDREDS of amino
acids long. You can start to see why we
have such long strands of DNA. The
MESSAGE is LONG!
tRNA reads the codon and
brings the specific amino
acid to the ribosome
Anticodon: The sequence of 3 bases on tRNA
that is complementary to a codon on mRNA
Codon Summary
• Triples of mRNA that code for a specific
amino acid
Translation Steps:
• 1) Make sure you have the transcribed strand.
Remember: it MUST be RNA! (Translation is
RNAprotein, NOT DNA protein)
• 2) Divide up strand into codons (sets of 3)
• 3) Use the Codon Chart to identify the amino
acid coded for by the codon (*This chart will
be GIVEN, you DON’T need to memorize it!)
Start and Stop Codons
• Just like journalists use quotation marks (“__”)
to indicate the beginning and end of a
quote....
• The ribosome needs a start and stop codon to
know when to start and stop ‘reading’ the
mRNA
Codon charts show the amino acid that an mRNA
codon calls for
Codon Practice
• Strand of DNA: A T G G T C A T C
• Strand of RNA: U A C C A G U A G
• Codons
U A C
Tyrosine
C A G
Glutamine
U A G
STOP
AGG TCT ACA ACT
mRNA
codon
tRNA
anticodon
amino acid
UCC
AGG
ser
AGA
UCU
arg
UGU
ACA
cys
UGA
ACU
stop
DNA:
mRNA:
TTACGTATC
AAUGCAUAG
Codons: AAU GCA UAG
Amino acids:asp
ala
stop
Panther Pass
1.
2.
3.
4.
5.
What is happening in transcription?
What is happening in translation?
Why do we need mRNA?
What is the function of tRNA?
DNA: A C G T C G G A T
mRNA:
amino acid sequence: