Download Some words to think about

DNA => RNA => PROTEIN
Central Dogma of Life
DNA
• Name: Deoxyribonucleic
Acid
• “Molecule of Life”
• Stays in the nucleus of eukaryotes
• Codes for RNA and ultimately
proteins
• Structure: Double
stranded (double helix)
• Monomers: Nucleotides
• Deoxyribose, phosphate
group, nitrogenous base
• N bases: Adenine, Guanine,
Cytosine, & Thymine
RNA
• Name: Ribonucleic Acid
• Disposable copy of DNA-
moves to the cytoplasm to
make proteins
• Structure: Single Stranded
• Monomer: Nucleotides
• Ribose, phosphate group,
nitrogenous base
• N base: Adenine, Guanine,
Cytosine, & Uracil
• Three kinds
• mRNA - messenger
• tRNA - transfer
• rRNA - ribosomes
Nucleotide
• Remember that a nucleotide is made up of three parts:
1. Phosphate group
2. 5 carbon sugar
3. Nitrogenous base
• The nitrogenous base differs
• A, T, C or G in DNA
• A, U, C or G in RNA
DNA Replication
• DNA must be replicated
• When does this happen during the cell cycle?
• When does DNA get replicated?
• When new cells need to be made
• To replace dead or damaged cells
• To grow and develop
• To form a new life- fertilization birth
• 2 strands of DNA run in opposite directions
DNA Replication
• Enzymes involved
• DNA helicase- unwinds, unzips double stranded DNA, exposes
nitrogenous bases so they can be based paired
• DNA polymerase- adds new DNA nucleotides
• DNA replication is semi-conservative, meaning that each
new DNA strand is made of one old and one new strand
Protein
• Monomers: Amino
Acids
• Functions:
• Enzymes
• Structural Proteins
• In the cell membrane
• Give characteristics to cells
• They make you,
YOU!
Genes
• Segments of DNA
• The code on the DNA
codes for a
PROTEIN.
How to get from DNA to Proteins
• Transcription - The
rewritten language of
DNA nucleotides to
RNA nucleotides
• Translation - The
translation from the
language of
nucleotides to the
language of amino
acids.
Transcription: From DNA => mRNA
• Rewriting the nucleotide
code
• In the Nucleus
• The DNA transcribed is
for a certain protein (from
a gene)
• DNA splits
• 1 Strand is used as a
template
• RNA polymerase is used
to build mRNA strand.
• Once complete the mRNA
goes into the cytoplasm.
Codons
• Series of 3
nucleotides on the
mRNA
• Each codon codes
from only on specific
Amino Acid
1 codon for 1 amino acid
Translation
From mRNA => Proteins
• mRNA comes from
the nucleus to the
Ribosome
• At the Ribosome, the
code of mRNA
nucleotides is
translated into the
language of Protein
amino acids using
tRNA
tRNA
• RNA molecules that
helps build proteins
• One end has an amino
acid attached
• One end has an
anitcodon
• Series of 3 nucleotides on
the tRNA
• Match with the mRNA
codons
• The amino acid is
specific to the anticodon
Translation
1.
mRNA enters the ribosome
•
Always starts with AUG on
mRNA
tRNA from the cytoplasm
attaches to the mRNA
3. Amino acid attached to tRNA
is dropped off
4. The next tRNA with the
matching anitcodon to the
next codon enters the
ribosome
5. The amino acid is dropped
off and tied to the 1st amino
acid…Until Stop Codon.
2.
tRNA
Amino Acid
Ribosome
What is the Protein?
• The series of Amino
Acids created in
translation
• The order of amino
acids determine the
protein
• Change the amino
acids, you change
the protein
Transcription and Translation Ex.
• DNA Sequence
• TACATACGCTTT
• Complementary RNA
• AUGUAUGCGAAA
• Amino Acid
Sequence
• Met-Try-Ala-Lys
Transcription and Translation Ex.
• DNA Sequence
• TACATACGCTTT
• Complementary RNA
• AUG/UAU/GCG/AAA
• Amino Acid
Sequence
• Met-Try-Ala-Lys
Mutations
• Occur when DNA is
replicated during the
cell cycle
• substitutions
• deletions
• insertions
Base Substitution
• One DNA nucleotide
is changed
• May or may not cause
a change in the protein
• No change = silent
mutation
• Could change amino
acid, and therefore the
function of the protein
Silent Mutation
• Original DNA
Sequence
• TACATACGCTTT
• Mutated DNA
Sequence
• TACATGCGCTTT
• Complementary RNA
• AUGUAUGCGAAA
• Complementary RNA
• AUGUACGCGAAA
• Amino Acid Sequence
• Met-Try-Ala-Lys
• Amino Acid Sequence
• Met-Try-Ala-Lys
Silent Mutation
• Original DNA
Sequence
• TACATACGCTTT
• Mutated DNA
Sequence
• TACATGCGCTTT
• Complementary RNA
• AUG/UAU/GCG/AAA
• Complementary RNA
• AUG/UAC/GCG/AAA
• Amino Acid Sequence
• Met-Try-Ala-Lys
• Amino Acid Sequence
• Met-Try-Ala-Lys
Mutation: Change in Protein
• Original DNA
Sequence
• TACATACGCTTT
• Mutated DNA
Sequence
• TACACACGCTTT
• Complementary RNA
• AUGUAUGCGAAA
• Complementary RNA
• AUGUGUGCGAAA
• Amino Acid Sequence
• Met-Try-Ala-Lys
• Amino Acid Sequence
• Met-Cys-Ala-Lys
Mutation: Change in Protein
• Original DNA
Sequence
• TACATACGCTTT
• Mutated DNA
Sequence
• TACACACGCTTT
• Complementary RNA
• AUG/UAU/GCG/AAA
• Complementary RNA
• AUG/UGU/GCG/AAA
• Amino Acid Sequence
• Met-Try-Ala-Lys
• Amino Acid Sequence
• Met-Cys-Ala-Lys
Base Insertion & Deletion
• Adding or taking
away of nucleotides
• Will change the
overall order of the
amino acids, and
therefore the Protein
will change
Mutation: Change in Protein
• Original DNA
Sequence
• TACATACGCTTT
• Complementary RNA
• AUG/UAU/GCG/AAA
• Amino Acid Sequence
• Met-Try-Ala-Lys
• Mutated DNA
Sequence
• TACAGTACGCTTT
• Complementary RNA
• AUG/UCA/UGC/GAA/A
• Amino Acid Sequence
• Met-Ser-Cys-Glu
Mutagens
• What causes
mutation
• UV light
• X-rays
• Chemicals
DNA => Protein