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DNA Lifes Code

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Nondisjunction: gamete gets extra or less chromosome (Down Syndrome- Trisomy 21) ... Down Syndrome: trisomy-21. Kleinfelter's syndrome: XXY. Patau syndrome: trisomy-13 ... – PowerPoint PPT presentation

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Title: DNA Lifes Code


1
DNA Lifes Code
  • Chapter 28

2
DNA/RNA Rap
  • C to G and G to C
  • A to T and T to A
  • That is the only way
  • When it comes to DNA!

3
  • C to G and G to C
  • A to U and U to A
  • That is the only way
  • When it comes to RNA!

4
DNA
  • Stands for deoxyribonucleic acid
  • Double helix shape like a twisted ladder
  • Made of nucleotides

5
  • Watson, Crick, Franklin scientists who figured
    out shape and structure of DNA

6
Nucleotide
  • Sugar Deoxyribose
  • Phosphate group
  • Nitrogen base

7
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8
  • There are 4 different kinds of nitrogen bases
  • Adenine (A)
  • Guanine (G)
  • Cytosine (C)
  • Thymine (T)

9
Complementary Base Pairing
  • A?T, G ?C
  • A will only fit with T
  • G will only fit with C

10
DNA and Chromosomes
  • DNA makes up the chromosomes found in the nucleus
  • Genes are small sections of chromosomes
  • Genes are short pieces of DNA
  • Each gene is made of a number of nitrogen bases
  • Genes determine your traits

11
Proof That DNA Controls TraitsExperiment A
  • Living harmless bacteria injected into mice
  • Mice live
  • Harmless bacteria cannot kill mice

12
Experiment B
  • Living pneumonia bacteria injected into mice
  • Mice die
  • Harmful bacteria can kill mice

13
Experiment C
  • Dead pneumonia bacteria injected into mice
  • Mice live
  • Dead, harmful bacteria cannot kill mice

14
Experiment D
  • Mixture of living, harmless bacteria and dead
    pneumonia bacteria are injected into mice
  • Mice die
  • The live harmless bacteria picked up DNA from the
    dead harmful bacteria DNA transformed the
    harmless bacteria into harmful bacteria

15
Nucleotides
  • DNA with
  • Nucleotides

16
How DNA Works
  • The order of the nitrogen bases determines the
    trait
  • A difference in the order of the nitrogen bases
    can cause a genetic disease like sickle cell
    anemia

17
  • The nitrogen bases in DNA spell out a message
    that is stored in code
  • Different orders of bases give different messages

18
Making Proteins
  • DNA directs protein synthesis in cells
  • The DNA cant leave the nucleus
  • Proteins are made at the ribosomes
  • Messenger RNA transcribes the DNA message and
    carries it from the nucleus to the ribosomes so
    proteins can be synthesized

19
  • The messenger RNA specifies which amino acids in
    what order are needed to make the protein
  • Transfer RNAs pick up the amino acids and bring
    them over to the ribosomes so the protein can be
    assembled

20
  • Traits show up in a cell because of the kinds of
    proteins being made at the ribosomes
  • The genes on the chromosomes sent their messages
    to the ribosomes to have specific traits appear
  • The kinds of proteins you have determine what
    traits you have

21
How DNA Copies Itself
  • DNA unzips
  • Loose nucleotides join their complementary bases
    on each single strand of DNA
  • Two identical strands are formed

22
DNA Replication
  • Result 2 exact copies original DNA

DNA Polymerase
Helicase
Replication fork
23
DNA coiled into Chromosome
24
DNA Replication, Accuracy Repair
  • Original A-T-T-C-C-G
  • Complement TAAGGC
  • Original GCTAAG
  • Complement
  • Original CTACCA
  • Complement
  • Original
  • Strand A GACCTA
  • Strand B
  • Mutation
  • Point mutation
  • Chemicals UV light
  • DNA proofreads repairs?1error/ 1Billion

25
RNA
  • Nucleotide
  • Ribose Sugar
  • Phosphate Group
  • Nitrogen Base
  • Adenine (A)
  • Guanine (G)
  • Cytosine (C)
  • Uracil (U) not T
  • Single Strand
  • 3 Types
  • Messenger RNA (mRNA)
  • Transfer RNA (tRNA)
  • Ribosomal RNA (rRNA)

26
3 Types of RNA
27
Transcription DNA? RNA
  • RNA Polymerase binds to DNA promoter site (begin
    gene)
  • Add complementary RNA nucleotides (U?A)

Gene Begins
RNA Polymerase
28
Transcription
  • DNA termination sequence signals gene end
  • RNA Polymersase releases DNA RNA

RNA Polymerase
RNA Strand
DNA Rewinds
29
Protein Synthesis Translation
  • Proteins polymers
  • Polypeptides sequence of amino acids
  • Genetic code
  • Codon 3 mRNA nucleotides code
  • Corresponds with tRNA anticodon amino acid
  • START Codon starts translation- 1 codon only?
    AUG
  • STOP Codon stops translation- 3 codons? UAA,
    UAG, UGA
  • Universal Codon-Amino Acid Code p. 303 (or
    tables)

30
mRNA Codon Codon Chart
  • AUG?
  • Methionine or
  • start codon
  • AAC?_______

Amino Acids
31
tRNA Ribosomes
Amino Acid Attachment Site
  • tRNA
  • In cytosol
  • Binds specific amino acid
  • Anticodon
  • complement to mRNA codons
  • Ribosomes
  • Free make proteins for cell
  • Attached make proteins for export membrane
  • 3 binding sites 1 for mRNA 2 for tRNA

32
Overview DNA? RNA? Protein
Transcription
Translation
33
Translation mRNA? Protein
  • mRNA leaves nucleus
  • Ribosome attaches to mRNA start codon
  • mRNA codon pairs with tRNA anticodon delivering
    amino acid
  • Peptide bond forms between amino acids
  • mRNA stop codon signals end of translation
  • mRNA released polypeptide complete

34
Translation Diagram
Polypeptide Chain
Peptide Bond
Nucleus
Amino Acid
tRNA
Anticodon
Codon
mRNA
Ribosome
35
Mutations
  • Types
  • Germ-cell mutations gametes?affect offspring
  • Somatic mutations body cells?affect individual
  • Lethal mutations v. beneficial mutations
  • 2 categories
  • Gene mutation? A.K.A. Point Mutations
  • Chromosomal mutation

36
Gene Mutations A.K.A. Point Mutations
  • Substitution? new codon
  • Sickle Cell Anemia substitute A for T

37
Gene Mutations (cont)
Deletion
  • Nucleotide deletions insertions
  • Frame-shift mutations
  • Changes amino acid sequence

Insertion
Deletion
38
Chromosomal Mutations
  • Deletion lose portion
  • ?
  • Duplication gain extra portion
  • ?
  • Inversion segment reverses
  • ?
  • Translocation transfer segment to non-homolgue
  • ?
  • Nondisjunction gamete gets extra or less
    chromosome (Down Syndrome- Trisomy 21)

39
Chromosome Mutations Diagrams
40
Genetic Traits Disorders
  • Disorders due to nondisjunction
  • Nondisjunction gametes have 1 more or less
    chromosome (pairs dont segregate)
  • Monosomy 45 chromosomes
  • Turners syndrome XO
  • Trisomy 47 chromosomes
  • Down Syndrome trisomy-21
  • Kleinfelters syndrome XXY
  • Patau syndrome trisomy-13
  • Edwards syndrome trisomy-18

41
Chapter 11-2 Cancer
  • Tumor uncontrolled cell division
  • Benign (cysts, warts)
  • Malignant Cancer
  • Metastasis cancer cells break off spread
  • Kinds
  • Carcinomas skin organ linings (breast lung
    CA)
  • Sarcomas bone muscle
  • Lymphomas tissues that make blood cells
  • Leukemia uncontrolled production WBC
  • Cancer Effects on Cell Cycle
  • Healthy cells stop dividing when crowded
  • Cancer cells keep dividing steal blood supply

42
Cancer Causes
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