What is the model for DNA replication?. Semiconservative wins!!
Dna replication model
-
Upload
punxsyscience -
Category
Technology
-
view
84 -
download
3
Transcript of Dna replication model
![Page 1: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/1.jpg)
DNA Replication ModelBy: Jessica Kerr
Pd. 1+2
![Page 2: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/2.jpg)
4. Free nucleotides base pair to
original polynucleotide.
5. DNA polymerase
enzyme joins the
sugar phosphate
backbone.
6. An enzyme rewinds the
double helix
7. Two new
double helices
each containing
one of the original
polynucleotides
Key:
Red arrow: Original double helix
Blue arrow: Helicase
DNA’s main job
is to store
information, it is
a nucleic acid
made up of
nucleotides
joined into long
strands or
chains by
covalent bonds.
The nucleotides
that make up
DNA are
Adenine,
Thymine,
Cytosine, and
Guanine.
![Page 3: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/3.jpg)
Unwinding-Replication
begins at a specific site in
the DNA called the origin
of replication. Unwinding
enzymes called DNA
helicases cause the two
parent DNA strands to
unwind and separate from
one another in both
directions at this site to
from two “Y”-shaped
replication forks. These
replication forks are the
actual site of DNA
copying.
Key:
-A polynucleotide chain can only elongate in one direction
-In the picture a new triphosphate is about to be added to
the growing chain.
![Page 4: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/4.jpg)
Complementary pairing up of the nucleotide bases- Each separate DNA strand
now has its sequence of bases exposed and unpaired. Enzymes match up each one of
these exposed bases, in turn, with free nucleotide triphosphates; A with T, and G with
C. It is therefore the sequence of bases on an old original strand which dictates and
specifies the complementary order of bases on the newly created strand.
Key:
-one of the new
polynucleotide chains can
elongate continuously.
-the other growing chain
does so in short lengths
which must later be joined
together.
![Page 5: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/5.jpg)
Continuous and Discontinuous- RNA are added to both strands of DNA in the 5’3’
direction. The replication fork opens unidirectional. The RNA primers are then extended in
the 5’ 3’ direction on both strands as DNA synthesis proceeds. On the leading strand,
synthesis is continuous because the primer is extended without interruption into the
replication fork as it continues to open to the right. On the lagging strand, synthesis is
discontinuous, since new RNA primers must be added as the opening of the replication
fork continues expose new template.
Key:
-One of the new
polynucleotide chains can
elongate continuously
-the other growing chain does
so in short lengths which
must later be joined together.
![Page 6: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/6.jpg)
DNA- Deoxyribonucleic Acid
![Page 7: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/7.jpg)
A-T
DNA builds up
nucleotides, Adenine
(A), Thymine (T),
Guanine (G), Cytosine
(C)
![Page 8: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/8.jpg)
A-T
G-C Cytosine- it’s a
compound found in living
tissue as a constituent
base of nucleic acids. It
is paired with guanine in
double strands DNA.
![Page 9: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/9.jpg)
A-T
G-C
C-G
Guanine-a compound
that occurs in guano and
fish scales, and is one of
the four constituent bases
of nucleic acids. A purine
derivative, it is paired with
cytosine in double
stranded DNA.
![Page 10: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/10.jpg)
A-T
G-C
T-A
C-GThymine- a compound
that is one of the four
constituent bases of
nucleic acids. A
pyrimidine derivative, it
is paired with adenine
in double-stranded
DNA.
![Page 11: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/11.jpg)
A-T
G-C
C-G
T-A
C-G
Adenine- a compound
that is one of the four
constituent bases of
nucleic acids a purine
derivative, it is paired
with thymine in double-
stranded DNA.
![Page 12: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/12.jpg)
A-T
G-C
C-G
T-A
C-G
G-C
Thymine pairs up with
Adenine
![Page 13: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/13.jpg)
A-T
G-C
C-G
T-A
T-A
C-G
G-C
Guanine pairs with
Cytosine
![Page 14: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/14.jpg)
A-T
G-C
C-G
T-A
T-A
C-G
G-C
A-t
The two DNA
strands run in
different
directions and are
anti-parallel.
![Page 15: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/15.jpg)
A-T
G-C
C-G
T-A
T-A
C-G
G-C
A-t
A-t
FINISHED DNA
![Page 16: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/16.jpg)
A-T
C-G
G-C
T-A
A
T
G
C
Unzipped DNA
![Page 17: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/17.jpg)
A-T
C-G
G-C
T-A
A
T
G
C
![Page 18: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/18.jpg)
A-T
C-G
G-C
T-A
Helicase
splits the
DNA in the
middle like
a zipper.
A
T
G
C
![Page 19: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/19.jpg)
A-T
C-G
G-C
T-A
A
T
G
C
A
T G
C
![Page 20: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/20.jpg)
A-T
C-G
G-C
T-A
A
T
G
C
A
T G
C
Free Nucleotides
![Page 21: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/21.jpg)
MutationsIn genetics, a mutation is a change of the nucleotide
sequence of the genome of an organism, virus, or extra
chromosomal genetic element.
Mutations result from unrepaired damage to DNA or to
RNA genomes (typically caused by radiation or chemical
mutagens)
Errors in the process of replication, or form the insertion
or deletion of segments of DNA by mobile genetic
elements.
![Page 22: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/22.jpg)
![Page 23: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/23.jpg)
Meiosis
Meiosis is a special type of cell division necessary for
sexual reproduction in eukaryotes, such as animals,
plants and fungi.
The number of sets of chromosomes in the cell
undergoing meiosis is reduced to half the original number.
![Page 24: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/24.jpg)
![Page 25: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/25.jpg)
![Page 26: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/26.jpg)
Chromosomes are
combined in this
phase.
![Page 27: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/27.jpg)
![Page 28: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/28.jpg)
Mitosis Mitosis is the process, in the cell cycle, by which a cell
duplicates into two genetically alike daughter cells.
In mitosis, chromosomes in the cell nucleus are separated
into two identical sets of chromosomes, each in its own
nucleus.
It is a form of nuclear division.
![Page 29: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/29.jpg)
Female
chromosome
Male chromosome
![Page 30: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/30.jpg)
Male
Female
![Page 31: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/31.jpg)
Male
Female
![Page 32: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/32.jpg)
![Page 33: Dna replication model](https://reader034.fdocuments.in/reader034/viewer/2022052509/55a18e561a28ab402d8b45b8/html5/thumbnails/33.jpg)
Citations/sources http://www.brooklyn.cuny.edu/bc/ahp/LAD/C4/C4_Stag
esReplication.html