Protein Synthesis & Mutations
All illustrations in this presentation were obtained from Google.com
Scientists
Who discovered the shape of the
DNA molecule and was awarded
the Nobel Prize?
Watson &
Crick
Who used X-rays to determine what
DNA really looked like?
Rosalind Franklin
Who actually found DNA is the “factor” that
caused good bacteria to change into bad
bacteria?
Avery
Remember: Avery
got an “A” for
finding DNA
Who used radioactive bacteriophages
(viruses) to confirm the genetic
material being transferred was DNA?
Bacteriophage
(Virus)
Bacteria Cell
Hershey & Chase
Bacteriophages chase after bacteria to inject
their DNA for infection and replication.
Real Picture of a
Bacteriophage
Who tried to find the genetic
material but failed? Instead he
found TRANSFORMATION.
This scientist
injected mice with
killed disease
causing bacteria
and good, live
bacteria and the
mice died of
pneumonia.
Griffith
F for failing to find genetic material!
F for finding:
Change from one thing to
another with transfer of
genetic material.
Who found:
% of Adenine = % Thymine
% Cytosine = % Guanine
What is this rule called?
CHARGAFF
The RULE OF BASE PAIRING!
DNA Structure
Empty
Slide
What does DNA stand for ?
What is its shape?
What is its function?
What sugar is in DNA?
Where is it found in Eukaryotes and
Prokaryotes?
DeoxyriboNucleic Acid
Double Helix
Carries the genetic code
to make proteins
(amino acid chain)
Deoxyribose sugar
Eukaryotes=nucleus
Prokaryotes=cytoplasm
What specific structures
carry the genetic code in
the nucleus?
Chromosomes
Name the 3 parts of a
DNA nucleotide
Phosphate Group
5-Carbon Sugar
(Deoxyribose)
Nitrogen Base
(A, T, C, or G)
Why is
DNA
Replication
important?
Replication =
make a copy
Important to
have 2 identical
DNA strands for
cell division
List the steps of DNA
replication:
1. Original double helix
unzips/unwinds
2. DNA Polymerase attaches to
make new strand of DNA
3. 2 New strands of DNA are
created with complimentary
nitrogen bases (A-T, C-G)
4. Two new double helix DNAs
are formed each with
one original strand and
one new strand
An original strand of DNA has these
nitrogen bases
CGGTATGAC
What are the complimentary bases for
the new DNA strand after replication?
What holds the nitrogen bases together
to form the “steps of the ladder”?
CGGTATGAC
l l
l
l l l l l l
GCCATACTG
original strand
Hydrogen Bonds
new strand
What is this protein
called that DNA wraps
around to coil up?
Histone
List Similarities and Differences
DNA
Similarities
RNA
Both are Nucleic Acids
Sugar Phosphate Backbones
A, C, G Nitrogen Bases
Differences
Deoxyribose Sugar
Thymine
Double Helix
Ribose Sugar
Uracil
Single Strand
List Similarities and Differences
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
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Name the 3 different types of RNA and
what do each do.
mRNA- brings genetic code for proteins from
DNA to ribosome (recipe)
tRNA- brings amino acids to ribosomes
(Sous chef)
rRNA- (ribosome) makes the protein (chef)
What does RNA stand for ?
How many different kinds are there?
What is its function?
What sugar is in RNA?
Where is RNA found?
What does RNA stand for ?
Ribonucleic Acid
How many different kinds are there?
3: mRNA, tRNA, rRNA
What is RNA’s function?
mtRNA
To make proteins
What sugar is in RNA?
Ribose sugar
mmRNA
Where is RNA found?
In the cytoplasm
rRNA
What is the process
of making proteins
that includes
transcription &
translation called?
What is the process
of making proteins
that includes
transcription &
translation called?
PROTEIN
SYNTHESIS
List the steps to make mRNA
What is this process called?
List the steps to make mRNA
“TRANSCRIPTION”
1.
2.
3.
4.
In the nucleus, DNA
unzips
RNA Polymerase binds
to DNA at promoter
region
RNA Polymerase reads
DNA genetic code
(nitrogen bases) and
makes complimentary
mRNA
mRNA goes out of
nucleus through pores
List the steps to make polypeptide chain
(protein) from mRNA
What is this process called?
List the steps to make protein
“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 chain =
PROTEIN
Polypeptide
Chain =
PROTEIN
tRNA
mRNA
What is the 3 base code on the mRNA
called?
What is the 3 base code on the mRNA
called?
Codon
What is the 3
base code on
the tRNA
called?
What is the 3 base
code on the tRNA
called?
Anti-codon
How many amino acids are there?
How many different codons code
for those amino acids?
How many amino acids are there? 20
How many different codons code for
those amino acids? 64
Remember:
Each tRNA only brings 1 amino
acid to the ribosome
1 codon = 1 amino acid
Translate this mRNA
A U G U G C G U C U A A
mRNA
A U G U G C G U C U A A
Met
Cys
Val Stop
Amino Acids
This is TRANSLATION!!!
What is a gene mutation?
Not a real
picture
Change in nucleotide sequence
Of the following mutations, which one
of these is not a gene mutation?
Substitution
Deletion
Insertion
Inversion
Gene mutation in mice.
Substitution = Point Mutation (gene)
Deletion = Frame Shift Mutation (gene)
Insertion = Frame Shift Mutation (gene)
Inversion = Chromosomal Mutation
I bet he can
catch 3x
more flies!
What type of gene mutation is it when
a nucleotide is inserted or deleted?
What type of gene mutation is it when
a nucleotide is inserted or deleted?
FRAME SHIFT MUTATION
Name all
types of
chromosomal mutations
What genes control the basic plan for
where organs and tissues are to go in an
embryo?
Hox Genes
NOT a real
picture!!!