1. DNA, RNA, and Gene Expression Chapter 14

2. Remember DNA’s structure allows it to do 3 things… DNA’s structure allows it to do 3 things… - But….the structure does NOT explain how the gene actually WORKS…. But….the structure does NOT explain how the gene actually WORKS…. -

3. DNA vs RNA - Sugar is - Sugar is - Contains - Contains - “Working copy” “Working copy”

4. Types of RNA - mRNA mRNA Ribosomal RNA Ribosomal RNA - tRNA tRNA

5. The Process of RNA Production RNA synthesis = - RNA synthesis = - Process: - Process: - A strand of DNA acts as a template A strand of DNA acts as a template RNA strand grows based on the complementary nucleotide of the parent strand RNA strand grows based on the complementary nucleotide of the parent strand - -

6. Transcription - Uses 1 strand as a template Uses 1 strand as a template -

7. Transcription RNA polymerase binds to - RNA polymerase binds to - - Once at the end, DNA and RNA strands are released Once at the end, DNA and RNA strands are released

8. Transcription

9. Post Transcriptions Modifications Not all nucleotides are involved in coding for proteins Not all nucleotides are involved in coding for proteins - - All can remain or some are removed in various combinations All can remain or some are removed in various combinations -

10. mRNAs Transcripts that become mRNA are further tailored Transcripts that become mRNA are further tailored - - 50-300 adenines 50-300 adenines

11. DNA vs. RNA DNA = “master blueprint” -. Don’t want to lose it!! DNA = “master blueprint” -. Don’t want to lose it!! RNA = “Disposable Copy”, “Working Copy” carries - RNA = “Disposable Copy”, “Working Copy” carries -

12. Question If the DNA strand below served as a template for an RNA molecule, what would be the complementary strand? If the DNA strand below served as a template for an RNA molecule, what would be the complementary strand? DNA : T G C T A C A A T DNA : T G C T A C A A T RNA : RNA :