Transcript Notes Mutations

Notes: Mutations
Objective: What are mutations and
how do they affect protein synthesis?
What are mutations?
 Changes in the DNA sequences that
affects the genetic information.
What causes mutations?
 Occur naturally (errors
during DNA replication)
 Caused by mutagens (UV
light, exposure to
chemicals, radiation, etc.)
 Most mutations are
harmless.
What is a point mutation?
 When
only
one nucleotide
is substituted
in the DNA.
Changes to this
base
What is a frame shift mutation?
If a nucleotide is
inserted or deleted
it changes the rest
of the nucleotide
sequence.
Look at the following strand of
DNA; describe what kind of
mutation occurred and how do
you know?
Before: G C A A C T T A C
After: G C A A T T A C
How are mutations passed on?
 Mutations need to
end up in gametes
(sex cells)
Mutations WS
Original DNA Sequence: T A C A C C T T G G C G A C G A C T
AU G U G G A A C C G C U G C U G A
mRNA Sequence:
_______________________________________________
MET TYP
ASP
ARG
CYS
STOP
Amino Acid Sequence:
_______________________________________________
USE THE ORGINAL DNA SEQUENCE ABOVE
TO COMPARE WHAT CHANGE HAPPENED
Mutated DNA Sequence #1: T A C A T C T T G G C G A C G A C T
What’s the mRNA sequence?
(Circle the change)
Compare with original, if it changed than YES there will be
Amino acid sequence?
an effect!!!!
Will there likely be effects? _______ What kind of mutation is this? _________________