moniqueand trevordna replication review for worksheets final
TRANSCRIPT
![Page 1: Moniqueand trevordna replication review for worksheets final](https://reader033.vdocuments.mx/reader033/viewer/2022060200/5598a7471a28ab89638b473b/html5/thumbnails/1.jpg)
By: Monique Hernandez
& Trevor Dunbar
![Page 2: Moniqueand trevordna replication review for worksheets final](https://reader033.vdocuments.mx/reader033/viewer/2022060200/5598a7471a28ab89638b473b/html5/thumbnails/2.jpg)
Why does DNA Replicate? To make an identical copy of DNA for cell division in Mitosis and
Meiosis
Meiosis is a specialized cell division process for sexual reproduction
Cell division for cells other than sex cells, is known as Mitosis
![Page 3: Moniqueand trevordna replication review for worksheets final](https://reader033.vdocuments.mx/reader033/viewer/2022060200/5598a7471a28ab89638b473b/html5/thumbnails/3.jpg)
Stages of Mitosis:
![Page 4: Moniqueand trevordna replication review for worksheets final](https://reader033.vdocuments.mx/reader033/viewer/2022060200/5598a7471a28ab89638b473b/html5/thumbnails/4.jpg)
First Step: Open Up the Double Helix
Where: Origin of Replication on DNA strand
![Page 5: Moniqueand trevordna replication review for worksheets final](https://reader033.vdocuments.mx/reader033/viewer/2022060200/5598a7471a28ab89638b473b/html5/thumbnails/5.jpg)
Key Players: DNA helicase: A protein that works to “unzip” the DNA
and separate the antiparallel strands
Single stranded binding proteins: keep the newly single stranded DNA stable and work to prevent hairpin helices on lagging strand
![Page 6: Moniqueand trevordna replication review for worksheets final](https://reader033.vdocuments.mx/reader033/viewer/2022060200/5598a7471a28ab89638b473b/html5/thumbnails/6.jpg)
How do chromosomes not get tightly tangled? Topoisomerase 1: works to relieve tension made in
DNA strand by making a break in the backbone of a single strand.
Topoisomerase 2: works to relieve tension during the “unzipping” of DNA by making a double stranded break.
http://www.youtube.com/watch?v=EYGrElVyHnU
![Page 7: Moniqueand trevordna replication review for worksheets final](https://reader033.vdocuments.mx/reader033/viewer/2022060200/5598a7471a28ab89638b473b/html5/thumbnails/7.jpg)
Second Step: Prime the DNA Strand
Leading Strand: Strand on which there is continuous synthesis of DNA
http://www.youtube.com/watch?v=dsoOPDgV0wc
![Page 8: Moniqueand trevordna replication review for worksheets final](https://reader033.vdocuments.mx/reader033/viewer/2022060200/5598a7471a28ab89638b473b/html5/thumbnails/8.jpg)
Leading Strand Key Players: Primase will add an RNA primer to the DNA strand.
DNA polymerase will bind to the RNA primer and begin synthesizing DNA in the 5’3’ direction
The clamp protein binds to DNA polymerase and prevents it from dissociating from the DNA template strand
![Page 9: Moniqueand trevordna replication review for worksheets final](https://reader033.vdocuments.mx/reader033/viewer/2022060200/5598a7471a28ab89638b473b/html5/thumbnails/9.jpg)
Lagging Strand Discontinuous synthesis of DNA; backstitches in the
5’3’ direction
The segments synthesized by DNA polymerase are called “Okazaki fragments”
http://www.youtube.com/watch?v=H_l0rnvPcTA
![Page 10: Moniqueand trevordna replication review for worksheets final](https://reader033.vdocuments.mx/reader033/viewer/2022060200/5598a7471a28ab89638b473b/html5/thumbnails/10.jpg)
Lagging Strand Key Players: Every ~100 nucleotides, RNA primers are added by a
DNA primase
DNA polymerase will let go of DNA once it meets the next RNA primer
Exonuclease will recognize RNA primer and cut it out.
DNA polymerase will fill in the missing gap with nucleotides
DNA ligase will seal the nicks in the strand
![Page 11: Moniqueand trevordna replication review for worksheets final](https://reader033.vdocuments.mx/reader033/viewer/2022060200/5598a7471a28ab89638b473b/html5/thumbnails/11.jpg)
![Page 12: Moniqueand trevordna replication review for worksheets final](https://reader033.vdocuments.mx/reader033/viewer/2022060200/5598a7471a28ab89638b473b/html5/thumbnails/12.jpg)
Chromosomes DNA and associated proteins
are organized into chromosomes
DNA + histone proteins= Chromatin
![Page 13: Moniqueand trevordna replication review for worksheets final](https://reader033.vdocuments.mx/reader033/viewer/2022060200/5598a7471a28ab89638b473b/html5/thumbnails/13.jpg)
Chromosomes
Genome of eukaryotes is too large to put on a single piece of DNA.
It is broken up into separate chromosomes
Each chromosome carries 1000’s of genes
Humans have 46 chromosomes
![Page 14: Moniqueand trevordna replication review for worksheets final](https://reader033.vdocuments.mx/reader033/viewer/2022060200/5598a7471a28ab89638b473b/html5/thumbnails/14.jpg)
Structure of a Chromosome
Telomere: ends of chromosomes, important for stability
Centromere: central region of chromosome, kinetochoresform here and the spindle microtubules attach