1. How DNA is used in Heredity Reading the Book of Life, or Gene Expression

2. DNA is precious – must be protected

3. A specific gene specifies a polypeptide –DNA is transcribed into RNA, which is translated into the polypeptide –We are polypeptdides Figure 10.6A DNA Protein TRANSCRIPTION TRANSLATION

4. RNA – the key to using DNA Ribo Nucleic Acid Single strand, 3 configurations sugar is Ribose No Thymine - Uracil Used to make the proteins from DNA coding

5. Types of RNA Messenger Transfer Ribosomal

6. 2 steps to Protein Synthesis

7. Transcription – use DNA gene to make “working copy” - mRNA In nucleus Enzyme –> RNA polymerase –Initiate at the “Promotor” –Elongate –Transcript made – End at the “Terminator”

8. An exercise in translating the genetic code Figure 10.8B Start codon RNA Transcribed strand Stop codon Translation Transcription DNA Polypeptide

9. Translation – protein synthesis DNA gene makes proteins (structural, enzymes, hormones) every 3 letters of transcribed mRNA is called a CODON Each CODON specifies a single AA –64 codons available to specify the 20 AA in nature Uses tRNA & rRNA

11. An exercise in translating the genetic code Figure 10.8B Start codon RNA Transcribed strand Stop codon Translation Transcription DNA Polypeptide

13. Editing the gene Eukaryotic cells have too much information coded (junk DNA) –message has to be “edited” –remove introns and keep exons

14. “Junk” DNA – 98% of our DNA code Editing the DNA Figure 10.10 DNA RNA transcript with cap and tail mRNA ExonIntron Exon Transcription Addition of cap and tail Introns removed Exons spliced together Coding sequence NUCLEUS CYTOPLASM Tail Cap

15. Mistakes in Protein Synthesis Changes to DNA code –Point mutations Deletion substitution frame shift mutation –Kinking of DNA Pyramidine dimer

16. Figure 10.16A Normal hemoglobin DNA mRNA Normal hemoglobin Glu Mutant hemoglobin DNA mRNA Sickle-cell hemoglobin Val

17. Types of mutations Figure 10.16B mRNA NORMAL GENE BASE SUBSTITUTION BASE DELETION ProteinMetLysPheGlyAla MetLysPheSerAla MetLysLeuAlaHis Missing

18. Are ALL mutations harmful?