DNA/RNA/Protein Synthesis
All illustrations in this presentation were obtained from Google.com
Griffith
F for failing to find genetic material!
F for finding:
He found that good
bacteria are changed into
bad bacteria with
transfer of some “factor.”
Avery actually found
DNA is the “factor”
that caused good
bacteria to change into
bad bacteria
Remember: Avery got
an “A” for finding DNA
Rosalind Franklin
used X-rays to determine what DNA
really looked like.
She died from too much radiation 
Watson & Crick discovered the
shape of the DNA molecule and
were awarded the Nobel Prize.
Hershey & Chase used radioactive
bacteriophages (viruses) to confirm the
genetic material being transferred was DNA
Hint: Bacteriophages “chase” bacteria
Bacteriophage
(Virus)
Bacteria Cell
Hershey & Chase
CHARGAFF
% of Adenine = % Thymine
% Cytosine = % Guanine
Chargoff’s Rule of BASE PAIRING!
A, T, C, G
Hint: You “Pee Urine” (purine)
in an outhouse attached to the
main house
Hint: Cystine and Thymine
have “Y” in their names like
Pyrimidine
DeoxyriboNucleic Acid
What is the shape of the DNA
molecule called?
DOUBLE HELIX
2 sides like a ladder
DNA carries the
genetic code to
make proteins
(amino acid chain)
What is the name of the
sugar that is in DNA?
Deoxyribose
What is the difference between the
DNA in Prokaryotes and Eukaryotes?
DNA in a
Prokaryote is a
long loop found in
the cytoplasm
DNA in a Eukaryote is
individual chromosomes in
the nucleus
What specific structures
carry the genetic code in the
nucleus?
Chromosomes
Name the 3 parts of a DNA
nucleotide
(building block / monomer)
1. Phosphate Group
2. 5-Carbon Sugar
(Deoxyribose)
3. Nitrogen Base
(A, T, C, or G)
1
2
3
Why is DNA Replication
important?
Cell Division!
Must have 2
identical strands of
DNA
Each has
one original strand
and
one new strand
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 identical double helix
DNAs are formed each with
one original strand and
one new strand
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
Hydrogen bonds hold the nitrogen
bases together to form the “steps of the
ladder”
Histone
This is the protein that
DNA wraps around to
coil up!
List 3 Similarities and Differences
DNA
Similarities
RNA
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
Remember:
RNA loves
“U”
mRNA- messenger RNA - brings genetic code for
proteins from DNA to ribosome (recipe)
tRNA – transfer RNA - brings amino acids to ribosomes
(sous chef)
rRNA – ribosomal RNA- (ribosome) makes the protein
(chef)
What does RNA stand for ?
Ribonucleic Acid
2. How many different kinds are
there?
3- mRNA, tRNA, rRNA
3. What is RNA’s function?
To make proteins
4. What sugar is in RNA?
Ribose sugar
5. Where is RNA found?
In the cytoplasm
rRNA
What is the whole process of
making proteins that includes
transcription & translation
called?
PROTEIN
SYNTHESIS
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 and edits it
mRNA goes out of
nucleus through pores
When RNA Polymerase is editing the mRNA during
transcription, what is kept in the mRNA and what is
edited (cut) out?
Exons –
Good - keep!
Introns –
Bad - get rid of
it!
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?
Codon
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
3 nitrogen bases = 1 codon
Can you Translate this
mRNA ?
A U G U G C G U C U A A
What is a gene mutation?
Change in nucleotide sequence
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!
POINT
MUTATION
What type of gene mutation is it when
insertion or deletion takes place?
FRAME SHIFT MUTATION
chromosomal mutations
HOX Genes control the basic plan for
where cells, tissues and organs are to
go in an embryo (organism)