Download Why is DNA Replication

Replication
Cell Division
DNA/RNA/Protein Synthesis
Griffith
“F” for failing to find genetic material!
But… He found TRANSFORMATION
Griffith thought smooth
bacteria produced a poison.
He injected mice with heat
killed smooth (bad) bacteria
with alive rough (good)
bacteria. Some “factor”
caused good bacteria to
change into bad disease
causing bacteria. This is
called:
TRANSFORMATION!
Avery
Avery got an “A” for finding DNA as
the transformation “factor” through
testing carbs, lipids, proteins, and
nucleic acids
Rosalind Franklin
Used X-rays to determine DNA was a
twisted double helix.
Created the first model of the DNA
and was awarded the Nobel Prize
Watson
&
Crick
Double Helix DNA Model
Hershey & Chase
Bacteriophages (viruses) that chase after bacteria to inject
their DNA for infection and replication.
Real Picture of a
Bacteriophage
CHARGAFF
Found:
% of Adenine = % Thymine
% Cytosine = % Guanine
Chargaff’s
Rules of BASE PAIRING!
Hint: You “Pee Urine”
(Purine) in an
outhouse attached to
the main house
Hint: Cystine and
Thymine have “y”
in their names like
Pyrimidine
REMEMBER: URACIL IS ALSO
A PYRIMIDINE
What does DNA stand for ?
DeoxyriboNucleic Acid
What is the shape of the DNA
molecule called?
DOUBLE HELIX
2 sides like a ladder
What is DNA’s function?
DNA carries the
genetic code to
make proteins
from amino acids
CODE FOR
ALL LIVING
THINGS!!!
What is the name of the sugar
that is in DNA (nucleotide)?
Deoxyribose
What is the difference between the
DNA in
Prokaryotes and Eukaryotes?
Cytoplasm
What are the specific structures that carry the
genetic code found in the nucleus?
Chromosomes
Name the 3 parts of a DNA
nucleotide
(building block = monomer)
Why is DNA Replication (making a copy of
the original DNA) important?
Cell Division!
Must have 2 identical strands of DNA
What are the steps of
DNA Replication?
(S phase of cell cycle)
1. DNA unzips
2. DNA Polymerase (enzyme)
attaches to the DNA and adds
complimentary bases (A,T,C,G) to
make new sides of DNA
3. Then, DNA Polymerase checks
and edits the new side to make
sure the proper nitrogen bases
are added.
4. Two identical strands of DNA are
created Each with one orig. side
+ one new side
2 new
DNA
Strands
What are the complimentary bases for the
new DNA strand after replication?
CGGTATGAT
l l
l
l l l l l l
GCCATACTA
Original strand
Hydrogen Bonds
New strand
What bond holds the nitrogen bases together to
form the “steps of the ladder”?
Histone
Protein that DNA
wraps around to coil
up
What is a Nucleosome?
Clusters of Histones with DNA wrapped around them.
Strawberry DNA
Extraction Lab
Why did we use…
1. Soap: Breaks down cell and
nucleus lipid membranes
2. Salt: Neutralizes (+) and (-)
charges
3. Meat tenderizer: Breaks down
the protein (Histones) that
DNA wraps around
4. Cold alcohol: Precipitates out
DNA
What does RNA stand for ?
Ribonucleic Acid
RNA
Uracil base
Hint:
RNA loves
“U” (Pyrimidine)
mRNA- messenger RNA - brings genetic code for
proteins out of DNA to ribosome
(like a recipe)
tRNA – transfer RNA - brings amino acids to ribosomes
(like a sous chef bringing ingredients to chef)
rRNA – ribosomal RNA- (Ribosome) makes the protein
(like the chef)
rRNA
mRNA
tRNA
List 3 Similarities and 3 Differences
MUST KNOW THIS!
DNA
RNA
Similarities
Both are Nucleic Acids
Sugar - Phosphate Backbones
A, C, G nitrogen Bases
Differences
Deoxyribose Sugar
Thymine base
Double Helix
Ribose Sugar
Uracil base
Single Strand
RNA
What is the
purpose of
RNA?
To make
PROTEINS!!!
Where is RNA found?
CYTOPLASM
What is the whole process of making
proteins that includes
transcription & translation called?
DNA → RNA → PROTEIN
PROTEIN
SYNTHESIS
DNA → RNA is called…
“TRANSCRIPTION”
1.
2.
3.
4.
In the NUCLEUS,
DNA unzips
RNA Polymerase
binds to DNA
RNA Polymerase
reads DNA’s
nitrogen bases and
makes and edits
mRNA
mRNA goes out to
cytoplasm through
the nuclear pores
RNA Polymerase edits the mRNA during transcription
RNA → Protein is called…
“TRANSLATION” (comes LATer)
1.
2.
3.
4.
In the CYTOPLASM, rRNA
attaches to mRNA
rRNA reads mRNA beginning
at the AUG “START codon”
Each tRNA brings 1 amino
acid to ribosome that has an
anti-codon to mRNA codon
until it reads a “STOP”
codon
Amino acids join to form
polypeptide (amino acid)
chain which is
PROTEIN
What is the 3 nitrogen base code on the
mRNA called?
Codon
3 Nitrogen bases = 1 Codon
1 Codon codes for 1 Amino Acid
tRNA
What is the 3 base
code on the tRNA
that matches with
the codon on
mRNA?
Anticodon
Each tRNA brings 1 amino acid to the ribosome
1 Codon = 1 Amino Acid
3 Nitrogen bases = 1 Codon
How many different amino acids are
there? 20
How many different codons code for
those amino acids? 64
Can you Translate this?
A U G U G C G U C U A A
Can you Translate this
mRNA ?
A U G U G C G U C U AA
Only if you have a codon wheel!
What is a gene mutation?
Change in nucleotide
sequence (A,T,C or G)
Substitution
Point Mutation
Insertion
Frame shift Mutation
What kind of DNA
mutations are
these?
GENE
MUTATIONS
Name each type
Substitution (Point Mutation)
Insertion (Frame shift)
Deletion (Frame shift)
Deletion
Frame shift Mutation
Types of Chromosomal Mutations
Which one of these is not a gene mutation?
Substitution
Deletion
Insertion
Inversion
Picture shows a gene mutation in
mice
What genes control the basic body plan
for where tissues and organs go in an
embryo (organism)?
Hox
Genes
Challenge: This is a strand of mRNA.
mRNA
AUCCGAGCUUGA
Can you figure out the piece of DNA that this came
from????
Keep studying