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PROTEIN SYNTHESIS

PROTEIN SYNTHESIS. P. P. S. S. P. P. S. S. P. P. S. S. P. P. S. S. P. P. S. S. P. P. REVIEW!. DNA Replication. Occurs when chromosomes duplicate An exact copy of the DNA is produced Hydrogen bonds between bases break and the molecule “unzips” with helicases

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PROTEIN SYNTHESIS

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  1. PROTEIN SYNTHESIS

  2. P P S S P P S S P P S S P P S S P P S S P P

  3. REVIEW! DNA Replication • Occurs when chromosomes duplicate • An exact copy of the DNA is produced • Hydrogen bonds between bases break and the molecule “unzips” with helicases • Each old strand of nucleotides serves as a template for each new strand • New nucleotides move into position according to Base Pair Rules with DNA polymerase

  4. DNA Replication Why does DNA replicate? Where does DNA replicate? When does DNA replicate?

  5. Protein Synthesis: The process of producing proteins

  6. Making Proteins! • DNA carries the instructions for producing proteins • Proteins are made of amino acids linked together • 20 different amino acids exist Where are proteins made?

  7. Why proteins?!? • Antibodies, enzymes and hormones • Hair, nails, muscles, skin Where do the amino acids come from??

  8. Proteins are made by Ribosomes!

  9. RNA • RNA: Single strand that carries genetic info from the DNA to the ribosomes!

  10. RNA Differs from DNA: 1. Sugar = Ribose 2. RNA contains the base Uracil (U) in place of Thymine (T) 3. Single-stranded

  11. An RNA strand is a disposable copy of a DNA segment!

  12. DNA/RNA Building Analogy • DNA is the official Master plan! • RNA is the cheap, disposable blueprint of the master plan

  13. The Base Pairs In RNA: Aalways pairs withU Calways pairs withG You just have to remember this! It stinks..but you just have to do it!

  14. Types of RNA . • Messenger RNA (mRNA) carries message from DNA to the ribosomes • Transfer RNA (tRNA) acts like a tow truck…taking amino acids to the ribosome

  15. The Genetic Code • Genetic language reads 3 lettersat a time • CODON: three consecutive nucleotides that specify a single amino acid. U C G C A C G G U is read as UCG-CAC-GGU which codes for Serine-Histidine-Glycine There are 64 combinations!

  16. Amino Acid Wheel Use the code by reading from thecenter to the outside Example: AUG codes for Methionine

  17. Name the Amino Acids! • GGG? • UCA? • CAU?

  18. Special Codons • Some codons are called the “Start Codons” or “Stop Codons” • These do not code for an amino acid • They just indicate the beginning and end of a protein!

  19. Protein Synthesis • Transcription • Translation

  20. 1) Transcription Transferring info from DNA to mRNA The DNA strand separates & one strand acts as a template for RNA. -Using rules of base pairs -Remember U instead of T!

  21. 2) Translation • The message in the mRNA is converted into proteins in the ribosome • The information is being TRANSLATED!

  22. During Translation: 1) mRNA goes to ribosome • Ribosomes read each codon one at a time • tRNA brings supplies for amino acid 3) Long chains of amino acids make proteins!

  23. Making a Protein DNA mRNA tRNA Protein

  24. Nuclear membrane DNA Transcription mRNA RNA Processing mRNA Ribosome Translation Protein DNA  RNA Protein Eukaryotic Cell

  25. (Single Strand) Transcription Translation

  26. Question: What would be the complementary RNA strand for the following DNA sequence? DNA = G C G T A T G RNA =

  27. Question: What would be the complementary RNA strand for the following DNA sequence? DNA = G C G T A T G RNA = C G C A U A C

  28. start codon A U G G G C U C C A U C G G C G C A U A A mRNA codon 1 codon 2 codon 3 codon 4 codon 5 codon 6 codon 7 stop codon protein methionine glycine serine isoleucine glycine alanine mRNA carries the info! Proteins are very IMPORTANT!!

  29. Mutation:Changes in genetic material • Like all mistakes, mutations can vary in shape & size! • Some mutations are neutral! • Some mutations are beneficial! • Some mutations are fatal!

  30. Mutations can occur naturally or be caused by environmental factors, such as: -X rays -Drugs -Chemical exposure -UV light -Tobacco smoke

  31. Point Mutations: Involve changes in one nucleotide and usually don’t cause major problems. -Substitution of one base • Frameshift Mutations:When an entire nucleotide is added or deleted, all of the following codons are shifted. • This may change every single amino acid which would greatly affect the protein

  32. Example of Point Mutation

  33. Example of Frameshift Mutation

  34. Mutations in sex cells can be passed down to offspring and be good or bad! • Can cause major problems • May become new genetic variation in a species!

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