• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
Dna replication with turning point
 

Dna replication with turning point

on

  • 4,934 views

 

Statistics

Views

Total Views
4,934
Views on SlideShare
4,933
Embed Views
1

Actions

Likes
3
Downloads
286
Comments
2

1 Embed 1

http://onlineacademy.bbsmoodle.com 1

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel

12 of 2 previous next

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
  • I'm doing National History Day this year and I used your powerpoint a s source. I Have to contact you and ask your name for it so I can put you on my annotated bibliography. If you would could you please give me that information? Thank you.
    Are you sure you want to
    Your message goes here
    Processing…
  • Thank you very much this note :)
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment
  • 15 minutes

Dna replication with turning point Dna replication with turning point Presentation Transcript

  • DNA and Replication
  • History of DNA
  • History of DNA
    • Early scientists thought protein was the cell’s hereditary material because it was more complex than DNA
    • Proteins were composed of 20 different amino acids in long polypeptide chains
  • Transformation
    • Fred Griffith worked with virulent S and nonvirulent R strain Pneumoccocus bacteria
    • He found that R strain could become virulent when it took in DNA from heat-killed S strain
    • Study suggested that DNA was probably the genetic material
  • Griffith Experiment
  • History of DNA
    • Chromosomes are made of both DNA and protein
    • Experiments on bacteriophage viruses by Hershey & Chase proved that DNA was the cell’s genetic material
    Radioactive 32 P was injected into bacteria!
  • Discovery of DNA Structure
    • Erwin Chargaff showed the amounts of the four bases on DNA ( A,T,C,G)
    • In a body or somatic cell:
    • A = 30.3%
    • T = 30.3%
    • G = 19.5%
    • C = 19.9%
  • Chargaff’s Rule
    • Adenine must pair with Thymine
    • Guanine must pair with Cytosine
    • The bases form weak hydrogen bonds
    G C T A
  • DNA Structure
    • Rosalind Franklin took diffraction x-ray photographs of DNA crystals
    • In the 1950’s, Watson & Crick built the first model of DNA using Franklin’s x-rays
  • Rosalind Franklin
  • Understanding DNA copyright cmassengale
  • Chromosomes are made of DNA and _____
    • Lipids
    • Proteins
    • Carbohydrates
    • Water molecules
    0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • According to Chargaff’s Rule Adenine must pair with ____ in DNA.
    • Guanine
    • Uracil
    • Thymine
    • Cytosine
    0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • According to Chargaff’s Rule Cytosine must pair with ____ in DNA.
    • Guanine
    • Uracil
    • Thymine
    • Adenine
    0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • Who built the first accurate model of DNA?
    • Rosalind Franklin
    • Chargaff
    • Watson and Crick
    • Griffith
    0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • DNA Structure
  • DNA
    • Two strands coiled called a double helix
    • Sides made of a pentose sugar Deoxyribose bonded to phosphate (PO 4 ) groups by phosphodiester bonds
    • Center made of nitrogen bases bonded together by weak hydrogen bonds
  • DNA Double Helix Nitrogenous Base (A,T,G or C) “ Rungs of ladder” “ Legs of ladder” Phosphate & Sugar Backbone
  • Helix
    • Most DNA has a right-hand twist with 10 base pairs in a complete turn
    • Left twisted DNA is called Z-DNA or southpaw DNA
    • Hot spots occur where right and left twisted DNA meet producing mutations
  • DNA
    • Stands for Deoxyribonucleic acid
    • Made up of subunits called nucleotides
    • Nucleotide made of:
    • 1. Phosphate group
    • 2. 5-carbon sugar
    • 3. Nitrogenous base
  • DNA Nucleotide O O=P-O O Phosphate Group N Nitrogenous base (A, G, C, or T) CH2 O C 1 C 4 C 3 C 2 5 Sugar (deoxyribose)
  • Pentose Sugar
    • Carbons are numbered clockwise 1’ to 5’
    C H2 O C 1 C 4 C 3 C 2 5 Sugar (deoxyribose)
  • DNA P P P O O O 1 2 3 4 5 5 3 3 5 P P P O O O 1 2 3 4 5 5 3 5 3 G C T A
  • Antiparallel Strands
    • One strand of DNA goes from 5’ to 3’ (sugars)
    • The other strand is opposite in direction going 3’ to 5’ (sugars)
  • Nitrogenous Bases
    • Double ring PURINES
    • Adenine (A)
    • Guanine (G)
    • Single ring PYRIMIDINES
    • Thymine (T)
    • Cytosine (C)
    T or C A or G
  • Base-Pairings
    • Purines only pair with Pyrimidines
    • Three hydrogen bonds required to bond Guanine & Cytosine
    C G 3 H-bonds
    • Two hydrogen bonds are required to bond Adenine & Thymine
    T A
  • Question:
    • If there is 30% Adenine , how much Cytosine is present?
  • Answer:
    • There would be 20% Cytosine
    • Adenine (30%) = Thymine (30%)
    • Guanine (20%) = Cytosine (20%)
    • Therefore, 60% A-T and 40% C-G
  • What sugar is in the side of all DNA molecules?
    • Glucose
    • Sucrose
    • Ribose
    • Deoxyribose
    0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • Deoxyribose binds to ____ on the sides of DNA molecules.
    • Ribose
    • Sulfur
    • Phosphates
    • Amino acids
    0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • What holds nitrogen bases together in DNA?
    • Phosphodiester bonds
    • Covalent bonds
    • Ionic bonds
    • Hydrogen bonds
    0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • A nitrogen base, a phosphate, and a deoxyribose make up a(n) ____
    • DNA molecule
    • Nucleotide
    • RNA molecule
    • None of the above
    0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • What is a double ringed nitrogen base called?
    • Purine
    • Pyridimine
    • Nucleotide
    • DNA
    0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • What are the two pyridimines found in DNA?
    • Adenine and Thymine
    • Cytosine and Guanine
    • Adenine and Cytosine
    • Thymine and Cytosine
    0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • If a molecule of DNA is 40% Adenine, how much guanine does it contain?
    • 10%
    • 20%
    • 40%
    • 60%
    0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • DNA Replication
  • Replication Facts
    • DNA has to be copied before a cell divides
    • DNA is copied during the S or synthesis phase of interphase
    • New cells will need identical DNA strands
  • Synthesis Phase (S phase)
    • S phase during interphase of the cell cycle
    • Nucleus of eukaryotes
    Mitosis -prophase -metaphase -anaphase -telophase G 1 G 2 S phase interphase DNA replication takes place in the S phase.
  • DNA Replication
    • Begins at Origins of Replication
    • Two strands open forming Replication Forks (Y-shaped region)
    • New strands grow at the forks
    Replication Fork Parental DNA Molecule 3’ 5’ 3’ 5’
  • DNA Replication
    • As the 2 DNA strands open at the origin, Replication Bubbles form
    • Prokaryotes (bacteria) have a single bubble
    • Eukaryotic chromosomes have MANY bubbles
    Bubbles Bubbles
  • DNA Replication
    • Enzyme Helicase unwinds and separates the 2 DNA strands by breaking the weak hydrogen bonds
    • Single-Strand Binding Proteins attach and keep the 2 DNA strands separated and untwisted
  • DNA Replication
    • Enzyme Topoisomerase attaches to the 2 forks of the bubble to relieve stress on the DNA molecule as it separates
    Enzyme DNA Enzyme
  • DNA Replication
    • Before new DNA strands can form, there must be RNA primers present to start the addition of new nucleotides
    • Primase is the enzyme that synthesizes the RNA Primer
    • DNA polymerase can then add the new nucleotides
  • DNA Replication
    • DNA polymerase can only add nucleotides to the 3’ end of the DNA
    • This causes the NEW strand to be built in a 5’ to 3’ direction
    Direction of Replication RNA Primer DNA Polymerase Nucleotide 5’ 5’ 3’
  • Remember HOW the Carbons Are Numbered! O O=P-O O Phosphate Group N Nitrogenous base (A, G, C, or T) CH2 O C 1 C 4 C 3 C 2 5 Sugar (deoxyribose)
  • Remember the Strands are Antiparallel P P P O O O 1 2 3 4 5 5 3 3 5 P P P O O O 1 2 3 4 5 5 3 5 3 G C T A
  • Synthesis of the New DNA Strands
    • The Leading Strand is synthesized as a single strand from the point of origin toward the opening replication fork
    RNA Primer DNA Polymerase Nucleotides 3’ 5’ 5’
  • Synthesis of the New DNA Strands
    • The Lagging Strand is synthesized discontinuously against overall direction of replication
    • This strand is made in MANY short segments It is replicated from the replication fork toward the origin
    RNA Primer Leading Strand DNA Polymerase 5’ 5’ 3’ 3’ Lagging Strand 5’ 5’ 3’ 3’
  • Lagging Strand Segments
    • Okazaki Fragments - series of short segments on the lagging strand
    • Must be joined together by an enzyme
    Lagging Strand RNA Primer DNA Polymerase 3’ 3’ 5’ 5’ Okazaki Fragment
  • Joining of Okazaki Fragments
    • The enzyme Ligase joins the Okazaki fragments together to make one strand
    Lagging Strand Okazaki Fragment 2 DNA ligase Okazaki Fragment 1 5’ 5’ 3’ 3’
  • Replication of Strands Replication Fork Point of Origin
  • Proofreading New DNA
    • DNA polymerase initially makes about 1 in 10,000 base pairing errors
    • Enzymes proofread and correct these mistakes
    • The new error rate for DNA that has been proofread is 1 in 1 billion base pairing errors
  • Semiconservative Model of Replication
    • Idea presented by Watson & Crick
    • The two strands of the parental molecule separate, and each acts as a template for a new complementary strand
    • New DNA consists of 1 PARENTAL (original) and 1 NEW strand of DNA
    Parental DNA DNA Template New DNA
  • DNA Replication – Take Notes copyright cmassengale
  • DNA Damage & Repair
    • Chemicals & ultraviolet radiation damage the DNA in our body cells
    • Cells must continuously repair DAMAGED DNA
    • Excision repair occurs when any of over 50 repair enzymes remove damaged parts of DNA
    • DNA polymerase and DNA ligase replace and bond the new nucleotides together
  • Question:
    • What would be the complementary DNA strand for the following DNA sequence?
    • DNA 5’-CGTATG-3’
  • Answer:
    • DNA 5’-CGTATG-3’
    • DNA 3’-GCATAC-5’
  • When is DNA copied?
    • Mitosis
    • Meiosis
    • G 1 Phase
    • S Phase
    • G 2 Phase
    20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • Where does DNA replication start?
    • Okazaki fragments
    • Leading Strand
    • Origins of Replication
    • Helicase binder
    20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • What enzyme unwinds DNA?
    • Helicase
    • Ligase
    • Single binding protein
    • DNA polymerase
    20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • What must be present before new DNA strands can form?
    • RNA polymerase
    • DNA polymerase
    • RNA primers
    • DNA primers
    20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • What enzyme adds nucleotides to DNA?
    • Helicase
    • Ligase
    • Single Binding Protein
    • DNA Polymerase
    20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • What direction is DNA made in?
    • 5’ to 3’
    • 3’ to 5’
    • It varies by species
    • None of the above
    20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • What enzyme joins Okazaki fragments together?
    • Helicase
    • Ligase
    • DNA Polymerase
    • Okazakiase
    20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • Each new DNA molecule is made of what?
    • 2 new strands
    • 1 new strand and 1 old stand
    • 2 old strands
    • It varies
    20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
  • What is the complimentary DNA for this sequence: 5’ GCTTAGA 3’
    • 5’ CGAATCT 3’
    • 5’ GCTTAGA 3’
    • 3’ CGAATCT 5’
    • 3’ GCTTAGA 5”
    20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34