Transcript Protein Synthesis (Translation)

12.3 Protein
Synthesis
(Translation)

Watch these animations and try to explain
what is going on.
◦ Animation 1
◦ Animation 2
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Transcription
happens in the
nucleus
mRNA moves out
of the nucleus into
the cytoplasm
Once in the
cytoplasm, mRNA
is used to make a
protein
Steps of Protein Synthesis
How does m-RNA tell the cell what
to do?
 mRNA
is a message that codes for a protein
 Proteins are made in the cytoplasm which work
to keep the cell alive
 Translation or protein synthesis is the
process of making a protein
 Proteins are made up of amino acids (small
building blocks)
 There are 20 different types of amino acids
1.
mRNA moves out of the nucleus and into
the cytoplasm
NUCLEUS
mRNA
Process of Translation
2. mRNA attaches to a ribosome (rRNA)
3. Transfer RNA (tRNA) decodes the mRNA
and brings amino acids to build up the
protein
Anticodon (3 bases on
tRNA): Matches up to
codons on mRNA
4. Protein (chain of amino acids) detaches
from ribosome and goes off to work in the
cell
-Each mRNA codon (3 bases) = 1 Amino
Acid
-Amino Acids link together= 1 Protein
Reading the Genetic Code
Start Codon= AUG (Methionine)
 Stop Codon= UAA, UAG, UGA (codes for
NOTHING!)
 WHY?

mRNA: AUG CCC GUA UGA
 Amino Acid Chain: Met-Pro-Val-Stop

mRNA: AUG UCG GCA UAA
 Amino Acid Chain: Met-Ser-Ala-Stop

Practice Using Your Codon Chart
Practicing the process
Transcription
Translation