Dec 22, 2015
Question of the Day
Question: Give the RNA sequence made from the DNA sequence ATGCTAGCT.
RNA
DNA
Nucleus
1’s Turn in: p. 353 A.Q. 1ab, 2b
UACGAUCGA
DNA RNA ProteinCentral Dogma of Molecular Biology:
• Transcription- creation of RNA using DNA
RNA
DNA
RNApolymerase
Nucleus
Part 1: Transcription
• Transcription- making RNA from DNA code in nucleus
Part 1: Transcription
1. Where does transcription take place?2. What enzyme is responsible for carrying out
transcription?3. What does transcription produce?
Discuss With Your Partner:
nucleus
RNA polymeraseRNA
Discuss with Your Partner:
• What does “translation” mean to you?• What are some ways that we could we
“translate” the following sentence:
When school is over, I am going to hang out with my friends.
Part 2: Translation
• Translation- using RNA instructions to build a protein
Part 2: Translation
• Translation- using RNA instructions to build a protein1. mRNA (messenger) carries code to cytoplasm2. mRNA is read 3 nucleotides at a time (1 codon)
Ex: AUG
Codon = 3 nucleotides
Part 2: Translation
3. 1 codon codes for 1 amino acid, which is transferred by tRNA
4. Anticodon part of tRNA must complement mRNA codonEx: AUG codon (mRNA) & UAC anticodon (tRNA)
anticodon
amino acidamino acid
amino acid
Part 2: Translation
5. Amino acids linked together by a ribosome to make a polypeptide
Part 2: Translation
6. Polypeptide is folded into a protein
PolypeptideProtein
Part 2: Translation
• Using codon wheel:– For decoding RNA– Work inside to
outside
Part 2: Translation
What amino acid does the codon AUG code for?
Methionine(start)
What amino acid does the codon GGG code for?
Glycine
What amino acid does the codon CAC code for?
Histidine
What amino acid does the codon UAG code for?
Stop(no amino acid)
• Using codon wheel:– For decoding RNA– Work inside to
outside– AUG = start codon– UAG, UAA, UGA =
stop codons
Part 2: Translation
Protein Synthesis Review:
Met-Gly-Arg
AUG-GGG-CGA-UAG
TACCCCGTGATCDNA:
mRNA:
Protein:
1. What codons…a. are in the RNA sequence AUGCCGUUUGGAUAG? b. What amino acids do they code for?
2. What codons…a. are in the RNA sequence AUGAAUGUUUGG? b. What amino acids do they code for?
3. What amino acids will the DNA sequence TATGCTAGACTG eventually code for?
Put ‘Em In Order!
a) tRNA molecules carrying amino acids and begin to match up with codons on the mRNA sequence according to the anticodons on the tRNA molecules
b) The polypeptide chain is finished and will later be folded into a complete protein
c) The mRNA leaves the nucleus and travels to the cytoplasm through pores in the nucleus
d) The amino acids are linked (bonded) together by a ribosome, a protein-building organelle
e) DNA is unwound by RNA polymerase and mRNA is created from the DNA sequence according to the base pairing rules
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