Transcript 8.5 Translation - Cloudfront.net

8.5 Translation
•Set up Cornell Notes on
pg. 9
•Topic: 8.5 Translation
•Essential Question:
1. Explain the connection
between a codon and
an amino acid.
2. Suppose a tRNA
molecule had the
anticodon AGU. What
amino acid would it
carry?
8.5 Translation
2.1 Atoms, Ions,
and Molecules
1. Explain the connection between a
codon and an amino acid.
2. Suppose a tRNA molecule had the
anticodon AGU. What amino acid
would it carry?
KEY CONCEPT
Translation converts an
mRNA message into a
polypeptide, or protein.
8.5 Translation
KEY CONCEPT
Translation converts an mRNA message into a
polypeptide, or protein.
8.4 Transcription
REVIEW:
• Transcription makes three types of RNA.
– Messenger RNA (mRNA) which was transcribed from
DNA, carries the message that will be translated to
form a protein.
– Ribosomal RNA (rRNA) forms part of ribosomes where
proteins are made.
– Transfer RNA (tRNA) brings amino acids from the
cytoplasm to a ribosome.
8.4 Transcription
What do you think of when you hear the word
translation?
• We usually think of
translating one language into
another
• Hello=Hola in Spanish
• Are the “words” exactly the
same?
• But, do they mean the same
thing? Do they have the
same message?
8.5 Translation
• Translation is a process that converts a message from
one “language” into another.
Hey, I know a joke! A squirrel walks up to a
tree and says, "I forgot to store acorns for the
winter and now I am dead." Ha! It is funny
because the squirrel gets dead.
8.5 Translation
Review:
Protein Synthesis Video
• Replication 1m40s
• Transcription 2m 50s
• Translation 4m 47s
8.5 Translation
• Translation converts mRNA messages into polypeptides
which make
proteins.
– mRNA can be translated into 20 different amino acids
8.5 Translation
• How can just four nucleotides (A, U, C, and G) be
translated into so many different amino acids?
• The same way 26 letters of the alphabet can be
translated into so many words.
– ape
– pea
The four letters of RNA are put together in
different combinations to form many different
“words”
–A
U
C
G
8.5 Translation
These “words” are called codons
• A codon is a sequence of three nucleotides that codes
for an amino acid.
codon for
methionine (Met)
codon for
leucine (Leu)
8.5 Translation
• Please draw and label this picture of a segment
of mRNA (pg. 8)
codon
codon
8.5 Translation
Separate this frame into “codons”: (top of pg. 8)
THECATATETHERAT
SISATETHEPIE
HISDOGWASHOT
HERFATCATSAT
8.5 Translation
Separate this frame into “codons”: (top of pg. 8)
THECATATETHERAT
THE CAT ATE THE RAT
SISATETHEPIE
SIS ATE THE PIE
HISDOGWASHOT
HIS DOG WAS HOT
HERFATCATSAT
HER FAT
CAT SAT
8.5 Translation
• The genetic code
matches each codon to its amino acid or
.
function.
•1st two
nucleotides
are the
most
important
8.5 Translation
Tell me what these genetic codes code for (pg. 8)
Codon
Amino Acid
1. GCC
2. AAA
3. AGC
4. UAG
5. AUA
6. AAU
7. GCA
8. CCG
9. UCA
10. AGG
8.5 Translation
1. GCC- alanine (Ala)
2. AAA- Lysine (Lys)
3. AGC- Serine (Ser)
4. UAG- stop codon
5. AUA- Isoleucine (Iso)
6. AAU- Asparagine (Asp)
7. GCA- Alanine (Ala)
8. CCG- Proline (Pro)
9. UCA- Serine (Ser)
10. AGG- Arginine (Arg)
8.5 Translation
– The Start codon codes for the
start of a gene segment
– AUG
– Three stop codons code for the
end of a gene segment
»UAG
»UAA
»UGA
8.5 Translation
• A change in the order in which codons are read changes
the resulting protein.
Please use your
genetic code
sheet to identify
the amino acid
for each codon
Label each
reading frame
8.5 Translation
• A change in the order in which codons are read changes
the resulting protein.
8.5 Translation
RANTHEFATCATSATONAHATHISSISWASMAD
RANTHEFATCATSATONAHATHISSISWA
RANTHEFATCATSATONAHATHISSISWA
8.5 Translation
• Regardless of the organism, codons code for the same
amino acid.
8.5 Translation
Get 3 colors
• Color 1- mRNA w/codons
• Color 2- tRNA (body/anticodon)
• Color 3- Amino Acid
8.5 Translation
• An anticodon is a set of three nucleotides that is
complementary to an mRNA codon.
Anticodon: AUG
Codon: UAC
– carried by a tRNA (transfer RNA).
8.5 Translation
Codon to Anticodon practice (mRNA  tRNA)
mRNA
Codon
AUG GUA AAA UUU AAU GGC UAG
tRNA
Anti-codon
UAC CAU UUU AAA UUA CCG AUC
8.5 Translation
• Ribosomes consist of two subunits.
– The large subunit has three binding sites for tRNA.
– The small subunit binds to mRNA.
8.5 Translation
8.5 Translation
1. tRNA binds to a start codon (AUG) and signals the
ribosome to assemble.
Amino
acid
AUG
Start
codon
8.5 Translation
2. A complementary tRNA anticodon binds to the exposed
codon
8.5 Translation
3. The ribosome helps form a polypeptide bond between
the amino acids.
– The ribosome pulls the mRNA strand the length of
one codon.
8.5 Translation
4. The now empty tRNA molecule exits the ribosome.
– A complementary tRNA molecule binds to the
next exposed codon.
8.5 Translation
5. This continues until a stop codon is reached (UAG,
UAA, or UGA)
-The ribosome releases the completed polypeptide
chain, now a protein, and disassembles.
Finished
PROTEIN
Protein
Synthesis in a Nutshell
8.5
Translation
Replication
DNA
AA G
A C G
DNA
______
______
(transcribe this piece)
Transcription
mRNA ______
______
codons
Translation
___
tRNA
______
___
______
T A G
_______
_______
___
_______
anticodon
Finished Product:____________!!!!!!
Amino Acids
Protein
Synthesis in a Nutshell
8.5
Translation
Replication
DNA
AA G
A C G
T T C ______
T G C
______
(transcribe this piece)
Transcription
AA G
A C G
mRNA ______
______
codons
Translation
DNA
tRNA
Lys
Thr
U
U C
______
UG C
______
T A G
A T C
_______
UA G
_______
Stop
AU C
_______
anticodon
A Protein
Finished Product:____________!!!!!!
Amino Acids
8.5 Translation
Transcription
8.5 Translation
Translation
8.5 Translation
Protein Synthesis; Translation Video 2m
8.5 Translation
Protein Synthesis Lab
In Pairs…
1. Get a DNA “Code #” from Mrs. M
2. Go to the Nucleus
• Write down the DNA strand
• Transcribe DNA into an mRNA strand
3. Go to the Ribosome (Rough E.R.)
• Write the tRNA anticodons
• Flip over anticodon cards to reveal secret message
4. Show Mrs. M
• Get a new code
Goal: At least 5 proteins synthesized
Each extra= EXTRA CREDIT
8.5 Translation
1. Explain the connection between a codon and an amino acid.
2. Compare the process of translation to translating Spanish into English.
3. Compare Start and Stop codons to the beginning and end of a sentence.
1. What is an anticodon?
For # 1-10- use the amino acid chart on pg. 244 to find which amino acids would
be encoded by the mRNA codes below:
1. GCC
2. AAA
3. AGC
4. UAG
5. AUA
6. AAU
7. GCA
8. CCG
9. UCA
10. AGG
8.5 Translation
1. Explain the connection between a codon and an amino acid.
A codon is a three-nucleotide sequence that codes for an amino acid.
1. Compare the process of translation to translating Spanish into English.
Just as we could translate English into Spanish, cells can translate an RNA message into
amino acids, to build proteins.
1. Compare Start and Stop codons to the beginning and end of a sentence.
A start codon (like the first word in a sentence) codes for the start of translation and the
start of an amino acid chain, the stop codon codes for the end of the amino acid chain
(like the period at the end of a sentence).
1. What is an anticodon?
A set of three nucleotides that is complementary to an mRNA codon.
1. GCC- alanine
2. AAA- Lysine
3. AGC- Serine
4. UAG- stop codon
5. AUA- Isoleucine
6. AAU- Asparagine
7. GCA- Alanine
8. CCG- Proline
9. UCA- Serine
10. AGG- Arginine