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Genomics to Proteomics

Genomics to Proteomics. DNA Replication Protein Synthesis. DNA Double Helix February 28, 1953…. Watson and Crick created a model of DNA by using Franklin’s and Wilkins’s DNA diffraction X-ray. D eoxy r ibo n ucleic A cid. Nucleotides: building blocks of DNA (and RNA).

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Genomics to Proteomics

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  1. Genomics to Proteomics DNA Replication Protein Synthesis

  2. DNA Double HelixFebruary 28, 1953… Watson and Crick created a model of DNA by using Franklin’s and Wilkins’s DNA diffraction X-ray

  3. Deoxyribonucleic Acid

  4. Nucleotides: building blocks of DNA (and RNA) • a 5-carbon deoxyribose sugar • a phosphate group • one of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), or thymine (T).

  5. DNA Nucleotides and Complementary Bases • Bonds Hold DNA Together • Nucleotides are linked by covalent bonds. • Complementary NBs are bonded by hydrogen bonds • Hydrogen bonding between the complementary base pairs, G-C and A-T, holds the two strands of a DNA molecule together.

  6. Complementary Base Pair Rules A—T T—A G—C C—G

  7. Practice… • Strand A ATGCTAGCTATTC • Strand B? (compliment) TACGATCGATAAG

  8. DNA Replication • process by which DNA is copied in a cell before a cell divides • When? • Remember the cell cycle? • Interphase • S phase • Synthesis of DNA is making a copy or replication!

  9. How DNA Replication Occurs Steps of DNA Replication 1. Replication begins with the separation of the DNA strands by helicases. 2. Then, DNA polymerases form new strands by adding complementary nucleotides to each of the original strands.

  10. DNA Replication & Enzymes 1. Primer—RNA/enzyme starter 2. Helicase • “Unzipper” • DNA Polymerase • “Putter-on-er” • Ligase • Glues fragments on the 1 side of DNA

  11. DNA Replication Each new DNA molecule is made of one strand of nucleotides from the original DNA molecule and one new strand.

  12. Prokaryotes vs. Eukaryotes

  13. DNA Errors in Replication • Changes in DNA are called mutations. • Enzymes proofread and repair prevent many replication errors. • From 1/100,000,000 (from DNA polymerase) errors1/1 billion errors • DNA Replication and Cancer • Unrepaired mutations that affect genes that control cell division can cause diseases such as cancer.

  14. And now a review… DNAi replication/transcription

  15. Protein Synthesis From DNA to Protein

  16. How Protein Synthesis Works… • DNARNAprotein. • The sequence of nucleotides in DNA contain information • information put to work through the production of proteins. • Proteins fold into complex, 3-D shapes to become key cell structures and regulators of cell functions.

  17. Enzymes • breaking down glucose molecules in cellular respiration, digesting food, or making spindle fibers during mitosis. • enzymes control all the chemical reactions of an organism. • Thus, by encoding the instructions for making proteins, DNA controls cells. • The sequence of nucleotides in each gene contains information for assembling the string of amino acids that make up a single protein.

  18. RNA

  19. RNA—nucleic acid RNA differs from DNA in 3 ways • 1st: RNA is single stranded—it looks like one-half of a zipper • 2nd: The sugar in RNA is ribose • 3rd: 4 nitrogenous bases A U G C • Uracil forms a base pair with adenine in RNA, just as thymine does in DNA.

  20. Types of RNA • messenger RNA(mRNA) • ribosomal RNA (rRNA) • transfer RNA (tRNA)

  21. 3 Types…3 Functions • mRNA carries the genetic “message” from the nucleus to the cytoplasm. • rRNA is the makes up most of the ribosome. • tRNA carries specific amino acids, helping to form proteins.

  22. During transcription, DNA acts as a template for directing the synthesis of RNA.

  23. Transcription 1 side of DNA is the template w/ the gene needed • RNA polymerase unwinds/"unzips" the DNA by breaking the hydrogen bonds between complementary nucleotides • RNA nucleotides are paired with complementary DNA bases. • RNA sugar-phosphate backbone forms with assistance from RNA polymerase. • Hydrogen bonds of the untwisted RNA+DNA helix break, freeing the newly synthesized RNA strand. • If the cell has a nucleus, the RNA is further processed and then moves through the small nuclear pores to the cytoplasm.

  24. Translation: From mRNA to Protein The process of converting the Info in a sequence of nitrogenous bases in mRNA into a sequence of amino acids in protein is known as translation. Translation takes place at the ribosomes in the cytoplasm. !!! In prokaryotic cells, which have no nucleus, the mRNA is made in the cytoplasm!!!

  25. So DNA can’t leave the nucleus… • Eukaryotic cells: mRNA is made in the nucleus and travels to the cytoplasm • In cytoplasm, a ribosome attaches to the strand of mRNA like a clothespin clamped onto a clothesline. • This is the role of transfer RNA.

  26. tRNA Amino acid Each tRNA molecule attaches to only one type of amino acid Chain of RNA nucleotides Transfer RNA molecule

  27. Anticodon Amino acid tRNA Ribosome mRNA codon

  28. Methionine tRNA anticodon

  29. TRANSLATE THIS! CODON: TAC ACA GAC UAU GGG ACU

  30. Start and stop • Usually, the first codon on mRNA is AUG, which codes for the amino acid methionine. • AUG signals the start of protein synthesis. • When this signal is given, the ribosome slides along the mRNA to the next codon.

  31. …or this one TRY THESE: AUG CGA AUU

  32. Amino Acid Chain Stop codon

  33. Introduction to Molecular Genealogy

  34. And now a review… DNAi replication/transcription

  35. DNA and RNA • Protein Synthesis

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