Big Idea #2 & 3: Structure Meets Function of Nucleic Acids Replication Transcription Translation.
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Transcript of Big Idea #2 & 3: Structure Meets Function of Nucleic Acids Replication Transcription Translation.
Big Idea #2 & 3: Structure Meets Function of Nucleic Acids
Replication
Transcription
Translation
Replication
• What function of DNA does this process accomplish?– Role of DNA polymerase
Diversity
• Mutation is the ultimate source for diversity.
• Mutation ONLY occurs during replication!
Transcription and Translation
Transcription
• Where?• Why is DNA read “backwards?”
• Molecules involved:– RNA polymerase:
Moves in the 5’ to 3’ direction…so what strand does it READ?
– DNA-->mRNA
Translation
• Where?• How does the concept
of structure meets function apply?
• Molecules involved:– mRNA “codons”– tRNA “anticodons”– rRNA
Function: DNA codes for proteins
• Actually “mRNA” is the “codon”
How can changing DNA
change a protein? A case study
• Sickle Cell:– What change in the
DNA alters the shape of the hemoglobin protein?
– Why does this change occur?
DNA Sequences
• HBB Sequence in Normal Adult Hemoglobin (Hb A Protein)– 3’CAAGTAAACATAGGACTTCTT 5’
• HBB Sequence in Mutant Adult Hemoglobin (Hb S Protein)– 3’CAAGTAAACATAGGACATCTT 5’
What to do?
• Determine the mutation that has been passed down (replication).
• Determine the Amino Acid sequence (using transcription and translation).
• Using an amino acid chart, determine WHY the shape change might occur. – Suggest what amino acid subsitutions may not have had
such a drastic effect. – Suggest which amino acid subsitutions would have a
similar effect.