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DNA/ RNA

DNA/ RNA. DNA. De oxyribo N ucleic A cid Made up of Nucleotides Contains deoxyrib ose sugar Contains the genetic (hereditary) code for all living organisms. Provides a “blueprint” or directions for all cellular processes. Nucleotide. DNA. DNA is found in the nucleus in Eukaryotic cells

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DNA/ RNA

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  1. DNA/ RNA

  2. DNA • DeoxyriboNucleicAcid • Made up of Nucleotides • Contains deoxyribose sugar • Contains the genetic (hereditary) code for all living organisms. • Provides a “blueprint” or directions for all cellular processes Nucleotide

  3. DNA • DNA is found in the nucleus in Eukaryotic cells • DNA is found in Chromosomes • In order of decreasing size • Nucleus  Chromosome  Gene DNA

  4. DNA • Discovered by Watson and Crick • They determined that DNA was in the form of a double helix (twisted ladder) • Sides of the ladder are made of sugar and phosphorous • Steps (rungs) made of nitrogenous base pairs

  5. DNA base pairs • Adenine • Thymine • Guanine • Cytosine • What are the base pair rules?

  6. DNA base pair rules • Adenine always attaches to Thymine • Guanine always attaches to Cytosine Example: • A-T and T-A • G-C and C-G

  7. DNA base pair practice Fill in the correct base pair sequence for the following: A- G- G- C- T- A- A-T G-C G-C C-G T-A A-T 

  8. More Practice T-A T-A A-T C-G G-C T-A C-G A-T G-C T T A C G T C A G 

  9. What would happen if the code was altered? Mutation: any change or alteration in the sequence of DNA (genetic material) Types: Deletion: one or more bases are removed(deleted) Example: AATCG  AACG The T was deleted

  10. More Mutations • Addition (aka Insertion): One or more bases are added • Example: AATTCGC  AATTCCGC A “C” was added Substitution: A base is replaced with a new base AATTGCG  AATGGCG The “T” was replaced with a “G”

  11. RNA • RiboNucleicAcid • Made of nucleotides • Contains Ribose sugar • Contains Uracil instead of Thymine • Is vital in making proteins • Is single stranded

  12. RNA base pair rules • There is only one difference in pairing the bases • Adenine always pairs with Uracil • Thymine still pairs with Adenine • Guanine still pairs with Cytosine • Example: A-U T-A G-C or C-G

  13. Protein Synthesis

  14. RNA • Two types • mRNA- • messenger RNA • translates the DNA code into codons • tRNA- • Transfer RNA • lines up amino acids in order of codons • Both used in protein synthesis at the ribosome

  15. Protein Synthesis • Protein Synthesis: The process of making proteins • Remember proteins are made from long chains of amino acids • The sequence(order) of the amino determines what type of protein is being made • This process will need: • DNA • RNA • mRNA • tRNA • Ribosome

  16. Protein Synthesis Steps • DNA Replication: DNA will “unzip” and copy itself • It will then “unzip” again to make a single strand that can make a strand of RNA • Transcription: The process of making an RNA sequence based on the DNA sequence.

  17. Transcription practice DNAUnzipped DNAmRNA (transcription) A-T A U T-A T A G-C G C G-C G C T-A T A A-T A U

  18. More Practice DNAmRNA A A GTTC A-U A-U G-C T-A T-A C-G

  19. Protein Synthesis • Translation:The process by which mRNA “translates” the genetic code into triple letter combinations that represent the key to figuring out the correct order of amino acids

  20. Protein Synthesis • Codon: The triple letter combination of nitrogenous bases (DNA Template) AATTTAAAGCCGGAT (mRNA) UUAAAUUUCGGCCUA Codons UUA AAU UUC GGC CUA Hint: to make codons, just break up the mRNA code into three letters

  21. Protein Synthesis • The codons will then be used to code for a particular Amino Acid • A chart will be used to determine the Amino acid • The first 3 letters are used to represent the Amino Acid • Always use mRNA for chart

  22. More Practice DNAmRNACodonAmino Acid A U A U UUC G CT AT A AAG C G Phe Lys

  23. Use this chart with your mRNA codons to determine amino acids • Start from the center and work your way out • AAG  Asp

  24. This chart can also be used to code for amino acids

  25. Protein Synthesis • Once codons are determined mRNA brings the information to the Ribosome. • It is there that the tRNA will transfer or bring the correct amino acid into place.

  26. Protein Synthesis • Transfer RNA (tRNA) will bring the correct amino acid into place • tRNA will match its code (anti-codon) to the mRNA codon • This will provide the correct sequence needed to make a protein • Remember: the sequence of Amino Acids determines what protein is being made The anti codon AAG matches up to the codon UUC This combination will always bring Pheinto place

  27. Random single amino acids STEP 1 DNA Replicates and mRNA created in the Nucleus STEP 2 mRNA leaves the nucleus bringing codon information to the ribosome tRNA STEP 3 tRNA brings the correct amino acid in to place based on the mRNA code

  28. Protein synthesis • STEPS • DNA copies itself (replicates) • mRNA matches up to DNA code following the rules of the base pairing (transcription) • mRNA translates DNA code into codons (triple letters) brings it to the ribosome • tRNA then “transfers” the amino acids into the correct order.

  29. Protein Synthesis • (DNA) AATTTAAAGCCGGAT • (mRNA) UUAAAUUUCGGCCUA Codons UUA AAU UUC GGC CUA tRNAAAU UUA AAG CCG GAU Amino Acids Leu Asp Phe Pro Asp A

  30. Mutations re-visited DNA code: AATGGCCCTAAT mRNA (codons): UUA CCG GGA UUA Amino Acids: Leu Pro GlyLeu

  31. Mutations re-visited • What happens if the DNA code on the previous slide has a substitution of a “G” at the first “T” DNA (with mutations): AAGCCGCCTAAT RNA: UUC GGC GGA UUA Amino Acids: PheGlyGlyLeu One simple change makes a completely different protein!!!!!!

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