In normal diploid organisms two copies of each chromosome are present in every somatic body cell 2n One from mom one from dad The last set are the sex chromosomes These may or may not be homologous ID: 1043322
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1. MUTATIONS
2. Chromosome Review…In normal diploid organisms, two copies of each chromosome are present in every somatic (body) cell (2n)One from mom, one from dadThe last set are the sex chromosomesThese may or may not be homologousPolyploid cells have multiple copies of one or more chromosome pairsTri-somy 21 (Down’s Syndrome)Klinefelter’s Syndrome (XXY)Monoploid cells have one or more unpaired chromosomesTurner’s Syndrome (X)
3. 2 chromatids make up 1 chromosomeEach autosome chromosome is paired with it’s homologous mateThe 23rd pair is the sex chromosomes.XX=FemaleXY=MaleNormally: 46 total(23 pairs)
4. Chromosome NumberMany different disorders which are caused by polyploidy or monoploidyYOU have to know 3!Down’s Syndrome (Tri-somy 21)Klinefelter’s SyndromeTurner’s Syndrome
5. Down’s Syndrome
6. Klinefelter’s Syndrome
7. Turner’s Syndrome
8. Gene MutationsOccur within a chromosome/chromatid:Point MutationInsertionDeletionDuplication (Amplification)InversionTranslocation
9. Point MutationSubstitution (Point Mutation)THE FAT CAT ATE THE RATTHE FAT CAT ATE THE HATMAY screw up one amino acid
10. InsertionInsertionTHE FAT CAT ATE THE RATTHE FAT CAT XAT ETH ERA T
11. DeletionDeletionTHE FAT CAT ATE THE RATTHE FAT ATA TET HER AT
12. Duplication (Amplification)
13. Inversion
14. Translocation
15. What Causes Mutations?There are many ways in which DNA can become mutatedNature!When DNA is copiedWhen Chromosomes separate in anaphaseMutagenic AgentsRadiationChemicalsUltra Violet Light CigarettesViruses & Bacteria
16. Can Mutations be Inherited?Yes and No!For a Mutation to be inherited, it must be in a gameteEgg or SpermIf it’s in an autosomal cell, it is not heritable!I cannot give my baby skin cancer…I can give my baby Down Syndrome (tri-somy 21 is due to non-disjunction in the gamete)
17. Then what??????So, there’s a mutation in the DNA…Then what? So what?Here’s where we start to tie ALLLLLLLL sorts of stuff together!
18. PROTEIN SYNTHESIS
19. DNA & RNADNA is the Master Plan…The “Recipe Book” made up of nucleotidesDNA cannot leave the nucleusDouble stranded – too big!mRNA is a copy of the DNA messageSingle stranded – just right!RNA travels to the RibosomeThe Ribosome reads 3 Nucleotides at a timeCodonThe Codon “codes” for a specific amino acidtRNA brings the amino acid to the ribosomeSo, the sequence of the DNA nucleotides determines the sequence of the amino acids!
20. DNA-Deoxyribonucleic AcidDNA makes up genesSequences of nucleotide basesRemember nucleotides??? Sun-House-Pool?Genes code for polypeptides (proteins)Proteins are used to build cells and do much of the work inside cellsProteins make YOU…YOU!
21. Genes & ProteinsProteins are made of amino acids linked together by peptide bonds (aka polypeptides)Remember? Amino Acids are the monomer of Proteins…They resemble a butterfly20 different amino acids exist
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23. DNA Begins the ProcessDNA is found inside the nucleusDNA is the instruction booklet for making every Protein the cell needsProteins, however, are made in the cytoplasm of cells by ribosomesRibosomes may be free in the cytoplasm (cytosol) or attached to the surface of rough ERBoth are Outside of the Nucleus!
24. Start with DNADNA‘s code (message) must be copied and taken out of the nucleusmRNA is the copy that leaves the nucleusIn the cytoplasm, this code must be read so amino acids can be bonded together to make the correct polypeptides (proteins)This entire process is called PROTEIN SYNTHESIS
25. Roles of DNA and RNADNA is the MASTER PLAN – the Entire Cook Book RNA is the BLUEPRINT of a portion of the Master Plan – the Recipe to be Made
26. RNA Differs from DNA – Remember?RNA has a sugar riboseDNA has a sugar deoxyribose
27. Other DifferencesRNA contains the base uracil (U) DNA has thymine (T)RNA is small and single-stranded DNA is large and is double-strandedDouble Helix
28. Structure of RNA
29. Three Types of RNAMessenger RNA (mRNA) - copies DNA code & carries the genetic information to the ribosomesRibosomal RNA (rRNA) - makes up the ribosomesTransfer RNA (tRNA) - transfers amino acids to the ribosomes where proteins are synthesizedYou only need to know mRNA and tRNA.
30. Two Steps…TRANSCRIPTION&TRANSLATION
31. Transcription CopyMessenger RNA (mRNA)Transcription happens in the NucleusDNA unzips & unwindsmRNA copies the DNA code & leaves through nuclear poresmRNA Contains the Nitrogen Bases A, G, C, U ( no T )
32. Transcription (Copy) Happens in the NucleusDNA unzips & unwindsEnzyme RNA Polymerase begins the process of making mRNAThe unpaired DNA nucleotides are used as a template for mRNA
33. Transcription - Messenger RNA (mRNA)Inside the nucleus – complementary mRNA nucleotides are paired up with the DNA templateThis makes a copy of the DNA sequence to make a specific proteinmRNA carries the information for the protein out of the nucleus to find a ribosome
34. Remember the Complementary Bases?On DNA: A-T C-GOn RNA: A-U C-GAll Thugs Carry GunsAll Underachievers Can’t Graduate
35. Transcription Example DNA sequence: TAC GGA CAT AAC ACC TGC ATCmRNA sequence AUG CCU GUA UUG UGG ACG UAGEvery point where DNA has the nucleotide Adenine (A) mRNA matches it with Uracil (U)Why? So our body knows which is the original template (DNA) and which is the transcribed copy (mRNA)
36. mRNA carries the messagemRNA carries the information for the protein out of the nucleus through the pores in the nuclear membrane
37. mRNA finds a RibosomeIn the cytoplasm, the mRNA locates a ribosome so the message can be translated and the protein madeRemember – Ribosomes are the site of protein synthesis!
38. Translation – Happens at the RibosomemRNA brings the transcribed (copied) message to the Ribosome (in the Cytoplasm)The Ribosome reads the mRNA nucleotide sequence 3 bases at a time (called a codon)tRNA brings the correct amino acid to the Ribosome based on the codonstRNA has an “anti-codon” based on complementary base pairingAll Underachievers Can’t Graduate!
39. Translation - Transfer RNA (tRNA)Clover-leaf shapeMolecule with an attachment site at one end for a specific amino acid Opposite end has three nucleotide bases called the anticodonWhich pair with the codon on the mRNAActs like a “taxi” for the amino acid
40. Transfer RNATranslates the nucleotide language into an amino acid languageTo create a polypeptideamino acidattachment siteUACanticodonMET
41. Codons and AnticodonsThe 3 bases of an anticodon are complementary to the 3 bases of a codon on the mRNAExample: Codon ACU Anticodon UGAU G AA C U
42. This is TranslationThe Ribosome reads the codons… tRNA taxis over the correct amino acids
43. The Genetic CodeA codon (3 nucleotides) calls for a specific amino acidAn amino acid may have more than one codonThere are 20 amino acids, but 64 possible codonsSome codons tell the ribosome to start and stop translatingAUG – methionine - start codonUAA, UAG, or UGA – stop codons
44. The Universal mRNA Codon ChartHow do WE know which amino acid is correct?Use the codon chart!Start with the first base Move to the second base…Finish with the third!
45. The Genetic Code You can use this codon chart too!But, the Regents likes the first one…Read from the center to the outsideExample: AUG codes for Methionine (the “start” codon)
46. Name the Amino AcidsCCC? _________UGA? _________CAC? _________GCA? _________AGA? _________CGU? _________
47. Name the Amino AcidsGGG? _________UCA? _________CAU? _________GCA? _________AAA? _________CGG? _________
48. What do these codons have to do with proteins?Each codon represents an amino acid that will be bonded together to form a protein Proteins are made of hundreds of amino acids in a specific sequenceWhen they get “out of order” a mutation occursLong string of amino acids will form
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