Transcript Mutations - The Super Heroes of Biology

Mutations
Part One
Definition
• Mutations are
changes to the
genetic material
(usually DNA
or RNA)
Mutation
• Mutations that
affect a specific
nucleotide are
known as point
mutations
• Mutations can also
affect a large
section of
DNA/chromosome
Mutation is the
only source
for new DNA
What causes mutations?
• Environmental
factors
• DNA Replication
– DNA Polymerase
Point Mutations
• Mutations
that change
one
nucleotide
in a gene
Point
Mutations
Substitution
Frameshift
No
Effect
Insertion
Effect
Deletion
Substitution: No effect
• One nucleotide is replaced by another
but it still codes for the same amino
acid
Substitution: Effect
• One nucleotide is replaced by another
and changes which amino acid it codes
for
Frameshift: Insertion
• Adds an extra nucleotide
• alters the codon sequence by
shifting the “frame” to the right
Frameshift: Insertion
THE CAT ATE THE RAT
THC ECA TAT ETH ERA T
Frameshift: Deletion
• Takes away (deletes) a nucleotide
• alters the codon sequence by shifting
the “frame” to the left
Frameshift: Deletion
THE CAT ATE THE RAT
THC ATA TET HER AT
Mutation Effects
• Mutations
can be
harmful,
neutral, or
helpful
Sickle Cell Anemia
•The difference between a normal
blood cell and a sickle cell
(one nucleotide)
Sickle Cell Anemia
• Mutated blood cell cannot carry
oxygen like the normal blood cell