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8.5 Translation. 2.1 Atoms, Ions, and Molecules. Set up Cornell Notes on pg. 9 Topic: 8.5 Translation Essential Question : Explain the connection between a codon and an amino acid. Suppose a tRNA molecule had the anticodon AGU. What amino acid would it carry?
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8.5 Translation 2.1 Atoms, Ions, and Molecules • Set up Cornell Notes on pg. 9 • Topic: 8.5 Translation • Essential Question: • Explain the connection between a codon and an amino acid. • Suppose a tRNA molecule had the anticodon AGU. What amino acid would it carry? • Don’t forget to add it to your T.O.Contents! • Explain the connection between a codon and an amino acid. • 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.
KEY CONCEPT Translation converts an mRNA message into a polypeptide, or protein.
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.
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?
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.
Review:Protein Synthesis Video • Replication 1m40s • Transcription 2m 50s • Translation 4m 47s
Translation converts mRNA messages into polypeptides which make proteins. • mRNA can be translated into 20 different amino acids
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
codon for methionine (Met) codon for leucine (Leu) These “words” are called codons • A codon is a sequence of three nucleotides that codes for an amino acid.
codon codon • Please draw and label this picture of a segment of mRNA (pg. 8)
Separate this frame into “codons”: (top of pg. 8) THECATATETHERAT SISATETHEPIE HISDOGWASHOT HERFATCATSAT
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
. • The genetic code matches each codon to its amino acid or function. • 1st two nucleotides are the most important
Tell me what these genetic codes code for (pg. 8) Codon Amino Acid • GCC • AAA • AGC • UAG • AUA • AAU • GCA • CCG • UCA • AGG
GCC- alanine (Ala) • AAA- Lysine (Lys) • AGC- Serine (Ser) • UAG- stop codon • AUA- Isoleucine (Iso) • AAU- Asparagine (Asp) • GCA- Alanine (Ala) • CCG- Proline (Pro) • UCA- Serine (Ser) • AGG- Arginine (Arg)
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
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
A change in the order in which codons are read changes the resulting protein.
RANTHEFATCATSATONAHATHISSISWASMAD RANTHEFATCATSATONAHATHISSISWASMAD RANTHEFATCATSATONAHATHISSISWASMAD
Regardless of the organism, codons code for the same amino acid.
Get 3 colors • Color 1- mRNA w/codons • Color 2- tRNA (body/anticodon) • Color 3- Amino Acid
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).
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
Ribosomes consist of two subunits. • The large subunit has three binding sites for tRNA. • The small subunit binds to mRNA.
1. tRNA binds to a start codon(AUG) and signals the ribosome to assemble. Amino acid AUG Start codon
2. A complementary tRNA anticodon binds to the exposed codon
3. The ribosome helps form a polypeptide bond between the amino acids. • The ribosome pulls the mRNA strand the length of one codon.
4. The now empty tRNA molecule exits the ribosome. • A complementary tRNA molecule binds to the next exposed codon.
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 Replication DNA A A G A C G T A G DNA ______ ______ _______ (transcribe this piece) Transcription mRNA ______ ______ _______ Translation tRNA ______ ______ _______ codons ___ Amino Acids ___ ___ anticodon Finished Product:____________!!!!!!
Protein Synthesis in a Nutshell Replication DNA A A G A C G T A G DNA ______ ______ _______ (transcribe this piece) Transcription mRNA ______ ______ _______ Translation tRNA ______ ______ _______ T T C T G C A T C A A G A C G U A G codons Lys ThrStop Amino Acids U U C U G C A U C anticodon A Protein Finished Product:____________!!!!!!
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
Explain the connection between a codon and an amino acid. Compare the process of translation to translating Spanish into English. Compare Start and Stop codons to the beginning and end of a sentence. 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: GCC AAA AGC UAG AUA AAU GCA CCG UCA AGG
Explain the connection between a codon and an amino acid. A codon is a three-nucleotide sequence that codes for an amino acid. 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. 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). What is an anticodon? A set of three nucleotides that is complementary to an mRNA codon. GCC- alanine AAA- Lysine AGC- Serine UAG- stop codon AUA- Isoleucine AAU- Asparagine GCA- Alanine CCG- Proline UCA- Serine AGG- Arginine