Week 8 Protein Synthesis

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Once DNA is replicated, the cell now needs to make
proteins. How does DNA’s message travel OUT of the
nucleus and INTO THE CELL, where the message gets
expressed as a protein???
This is known as…
About RNA…
• RNA = Ribose Nucleic Acid
• Similar to DNA, but…
• Smaller & single stranded
• Sugar = “Ribose” NOT “Deoxyribose”
• 1 nitrogen base is different, Uracil; there is NO THYMINE in
RNA
• Adenine, Uracil, Cytosine,
Guanine
• Do you remember the base paring
rules???
DNA to RNA Practice
DRAW ME 
DNA to RNA Practice
DRAW ME 
Types of RNA used during
Protein Synthesis
1. mRNA = Messenger RNA
2. rRNA = Ribosomal RNA
3. tRNA = Transfer RNA
What is “Protein Synthesis” ?
• Protein synthesis is the process of making a
protein from DNA.
• There are 2 parts used during protein synthesis:
1. Transcription
2. Translation
Transcription
• The synthesis of mRNA from a
DNA blueprint
• A new strand is “written”
from the DNA strand
• Occurs in the NUCLEUS, then
the mRNA travels OUT of
the nucleus
Translation
1. The information in the
mRNA is translated by
a ribosome (made of
rRNA) who “reads” it.
2. Transfer RNA (tRNA)
enters the ribosome to
drop off an amino acid
3. A chain of amino acids
then exits the ribosome
and folds into a protein
Protein Synthesis Animation
• http://www.youtube.com/watch?v=kgGVk9NExxw
&feature=related
• Transcription and protein assembly
Protein Synthesis Animation
• https://www.brainpop.com/science/cellularlifeandgenetics/rna/
• Transcription and protein assembly
Create a “T” chart
One side, write DNA, the other
write RNA
Class review!
Summary of Protein Synthesis
1. DNA opens
2. Free floating bases connect to the exposed DNA
bases making mRNA (Transcription)
3. mRNA travels OUT of the NUCLEUS and into the
CYTOPLASM
4. Ribosome (rRNA) “reads” the mRNA and a tRNA
drops off an amino acid
5. The amino acid chain exits the ribosome and folds
up into a protein 
Codon VS Anticodon
• CODON: 3 nucleotides in mRNA.
Each codon will code for a single
amino acid
• ANTICODON: 3 nucleotides in
tRNA that pair to a codon
Codon VS Anticodon Video 
• http://www.youtube.com/watch?v=B6O6uRb1D38
What are amino acids?
• Amino acids are the building blocks of proteins
• A chain of amino acids are needed to create a
protein
What happens to the chain?
• Individual amino acids
bind together
• Folds up
• Becomes a protein
What is a Protein?
• Proteins are made of 20 different amino acids
• The sequence (pattern) of amino acids will vary
between each protein
• The sequence of an amino acid will tell its
shape, how to fold and its function (job)
Codon chart practice! 
• DNA:
• mRNA:
• rRNA:
• tRNA:
A- T- T- G- C- A- G- A- T- G- C- A
Using the Codon Chart, find the amino acid of
tRNA’s anticodon 
• Amino Acid: ___________, ____________,
__________ & ___________
The genetic code is used to
determine the amino acid
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