Chapter 13 Notes

1. Chapter 13 Notes RNA and Protein Synthesis

2. 13-1 RNA and Protein Synthesis RNA, like DNA, consists of long chains of nucleotides. Three differences between DNA and RNA - the sugar is ribose - single stranded - contains uracil (U) instead of thymine

3. 13-1 RNA and Protein Synthesis Genes are coded DNA instructions that control the production of proteins. - each gene controls the production of a specific protein - DNA (gene)  specific RNA sequence  specific amino acid sequence

4. 13-1 RNA and Protein Synthesis

5. 13-1 RNA and Protein Synthesis There are three types of RNA: messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA) mRNA: carries copies of instructions from DNA to the rest of the cell rRNA: along with proteins, makes ribosomes

6. 13-1 RNA and Protein Synthesis

7. 13-1 RNA and Protein Synthesis Ribosome Ribosomal RNA

8. 13-1 RNA and Protein Synthesis Amino acid Transfer RNA

9. 13-1 RNA and Protein Synthesis tRNA: transfers the message to the amino acid sequence Transcription: the copying of the DNA into a complementary strand of RNA - uses the enzyme RNA polymerase

10. 13-2 RNA and Protein Synthesis • During transcription, RNA polymerase binds to DNA and separates the DNA strands. • RNA polymerase then uses one strand of DNA as a template from which nucleotides are assembled into a strand of RNA. • The enzyme binds to the region DNA known as the promoter region.

11. 13-2 RNA and Protein Synthesis Adenine (DNA and RNA) Cystosine (DNA and RNA) Guanine(DNA and RNA) Thymine (DNA only) Uracil (RNA only) RNApolymerase DNA RNA

12. 13-2 RNA and Protein Synthesis RNA Editing Before it leaves the nucleus, RNA is edited. Splicing occurs by removing introns and fusing exons together.

13. 13-2 RNA and Protein Synthesis Exon Intron DNA Pre-mRNA mRNA Cap Tail

14. 13-3 RNA and Protein Synthesis The Genetic Code The genetic code is read in three letter segments called codons. There are 64 different codon possibilities -there are only 20 different amino acids that they code for -AUG is the start codon - there are 3 stop codons

15. 13-3 RNA and Protein Synthesis

16. 13-3 RNA and Protein Synthesis

17. 12-3 RNA and Protein Synthesis Translation: the decoding of mRNA into an amino acid sequence During translation, the cell uses information from messenger RNA to produce proteins - anticodon: the three letter sequence on tRNA that binds with mRNA Protein synthesis animation

18. 12-3 RNA and Protein Synthesis Nucleus mRNA

19. 13-3 RNA and Protein Synthesis Lysine Phenylalanine tRNA Methionine Ribosome mRNA Start codon

20. 13-3 RNA and Protein Synthesis Lysine tRNA Translation direction mRNA Ribosome

21. 13-3 RNA and Protein Synthesis Polypeptide Ribosome tRNA mRNA

22. Section Quiz The role of a master plan in a building is similar to the role of which molecule? • messenger RNA • DNA • transfer RNA • ribosomal RNA

23. Section Quiz A base that is present in RNA but NOT in DNA is • thymine. • uracil. • cytosine. • adenine.

24. Section Quiz The nucleic acid responsible for bringing individual amino acids to the ribosome is • transfer RNA. • DNA. • messenger RNA. • ribosomal RNA.

25. Section Quiz A region of a DNA molecule that indicates to an enzyme where to bind to make RNA is the • intron. • exon. • promoter. • codon.