DNA for Dummies (and the intellectually astute)

1
DNA for Dummies(and the intellectually astute)

• A Dr. Parrott Production

2

• Secret of Photo 51
• Ribosome orchestrates this event

3
DNA Wrap Basic DNA Wrap Advanced Chromosome
Packing DNA Coiling
4
Replication DNA?DNA

• Occurs during S phase of interphase in
  reproducing cells only
• DNA template is copied complimentarily and semi
  conservatively
• Occurs only in the nucleus

5
Meselson-Stahl Experiment How DNA Replicates DNA
Replication Bidirectional Replication Replication
Complete
6
Make a DNA strand complimentary to the
following DNA ATG GTG CAC CTG ACT CCT GTG GAG
AAG TCT DNA TAC mRNA Amino Acids tRNA
7
DNA Replication Basic DNA Replication Fork Rep
Fork 2 DNA Replication DNA Polymerase
8
Tran scription DNA?mRNA

• Occurs continually throughout the cell cycle with
  the exception of mitosis
• Occurs in the nucleus as messenger RNA copies DNA

9
Transcription Basic RNA Splicing Protein
Synthesis Transcription Transcription Complete
10
Make a DNA strand complimentary to the
following DNA ATG GTG CAC CTG ACT CCT GTG GAG
AAG TCT DNA TAC Transcribe the above DNA
template into an mRNA mRNA UAC Amino
Acids tRNA
11
Translation mRNA?protein

• Occurs continually throughout the cell cycle
• Occurs at the ribosome as it
• reads the mRNA codons
• Matches codons to amino acids
• Prompts tRNA to bring a.a.
• Attaches a.a. with peptide bonds

DNA to Protein
12
(No Transcript)
13
Translation

• tRNA anticodon is complimentary to mRNA codon
• tRNA is specific to the amino acid it brings
• Peptide bonds connect amino acids to form
  polypeptide (protein)

Translation Basic Translation Advanced Protein
Synthesis Protein Synthesis 2
14
Protein Synthesis
15
Make a DNA strand complimentary to the
following DNA ATG GTG CAC CTG ACT CCT GTG GAG
AAG TCT DNA TAC mRNA (codons) UAC Translate
the above mRNA strand into an amino acid sequence
(protein) Amino Acids Tyrosine tRNA
(anticodons)
16

• Watch RNAi Online http//www.pbs.org/wgbh/nova/sc
  iencenow/3210/02.html

17
Make a DNA strand complimentary to the
following DNA ATG GTG CAC CTG ACT CCT GTG GAG
AAG TCT DNA TAC mRNA (codons) UAC Amino
Acids Tyrosine What are the anticodons on the
tRNA for the above strands? tRNA (anticodons) AUG
18
To summarize
19
Mistakes/Mutations

• Mutation? any permanent alteration in the
  sequence of DNA bases
• Point mutations can result in frameshifts in the
  reading frame
• Chromosomal mutations can result in translocations

20
Mistakes/Mutations

• Silent mutation? change in n.t. sequence, but no
  change in product
• Missense mutation? swapping of a.a. (sickle cell
  anemia, PKU)
• Nonsense mutation? insertion of stop codon into
  sequence

21
Resources

• Genetics Movies http//www.dpo.uab.edu/landrews/
  genetics.htm
• DNA Tutorial http//www.ncc.gmu.edu/dna/index.htm
  
• Bacterial Replication Animations
  http//www.wwnorton.com/college/biology/mbio/anima
  tions/dna_replication.asp
• Telomere Synthesis (shortening of linear
  chromosomes) http//spine.rutgers.edu/cellbio/ass
  ets/flash/tel.htm
• Gene Processing
• http//highered.mcgraw-hill.com/sites/0072437316/s
  tudent_view0/chapter15/animations.html
• Replication Animations http//highered.mcgraw-hil
  l.com/sites/0072437316/student_view0/chapter14/ani
  mations.html
• Gene Expression Animationshttp//highered.mcgraw-
  hill.com/sites/0072437316/student_view0/chapter18/
  animations.html
• Gene Technology http//highered.mcgraw-hill.com/s
  ites/0072437316/student_view0/chapter16/animations
  .html