Transcript 4_mutations.ppt

MUTATIONS
Remember: Before RNA can be transcribed, the two
separate between the
strands of DNA must first __________
nitrogen bases
______________.
The 4 nitrogen bases in DNA are:
A
Adenine
G
C
T
Guanine
Cytosine
Thymine
The 4 nitrogen bases in RNA are:
A
Adenine
G
C
U
Guanine
Cytosine
Uracil
Q: What are the 3 types of RNA?
messenger RNA
(mRNA)
transfer RNA
(tRNA)
ribosomal RNA
(rRNA)
Remember: All living things contain genetic
DNA
material in the form of ________.
D
N
A
deoxyribonucleic _____.
acid
DNA stands for ________________
nucleotides
A nucleic acid is a long chain of ____________.
DNA contains the
instructions for
making all of the
_________
proteins
within a cell.
Inside of the cell’s nucleus, the DNA is wound
and wound into very large and complex units
of DNA known as ______________.
chromosomes
THE CENTRAL DOGMA
DNA
transcription
RNA
translation
proteins
Write a 2-word sentence describing
what happened to the DNA
It changed!
sequence shown: __________
The information for making proteins
sequence
is carried in the _________
of the
nitrogen bases
_______________.
The order of
the bases is
what makes
the difference!
Whenever there is any
change to a DNA sequence, it
is called a __________.
mutation
This change can be large, like an entire
chromosome breaking, or it can be small,
like the single change shown above. The
size of the change does not matter.
Q: If mutations are just a change to
the DNA, can they sometimes be
good thing?
Yes, change can be good so
A: _____________________________
mutations can be good.
_______________________________
How mutations occur:
reproduces or
Natural mutations occur when an organism ___________
repairs DNA incorrectly, but these occurrences are very
_________
chemicals or
rare. Mutations can be induced by either ____________
high energy __________.
radiation Anything that causes a mutation to
mutagen
an organism’s DNA is referred to as a __________.
Q: Which forms of radiation can be harmful to an organism’s
DNA?
Ultraviolet, x-rays and gamma rays can all damage DNA.
A: __________________________________________________
Thymine dimer induced by UV light.
There are three types of
mutations that you should be
familiar with: insertions,
deletions and point mutations.
Below is a strand of DNA and 3
mutated versions of that strand.
Decide which strand is the
insertion, which is the deletion
and which is the point mutation.
point mutation
insertion
deletion
Interpreting Mutations:
You must understand that a change to the DNA will first
RNA
cause a change to the _______.
And a change to the RNA may result in a change to the
protein it describes.
________
Gamete cells are the cell that are used to make
offspring. Males produce gamete cells known
sperm
as ___________
and females produce gamete
cells known as an ________
ovum or _______.
egg
Important Fact: Only mutations that occur in a
_________
gamete cell can be passed on to offspring when
an organism reproduces sexually.
In order to interpret how a mutation will affect an organism,
amino acids in the proteins
the change to the sequence of ________
must be determined. This means that you must translate the
mRNA strand from before and after the mutation.
Using your codon chart, determine how the following
mutations would affect the resulting protein.
proline – leucine – threonine
5’ CCGUUGACC 3’
proline – stop

5’ CCGUAGACC 3’
1. The chain above represents three codons. Which of the following
changes would be expected in the amino acid chain if the mutation
shown above occurred?
A The amino acid sequence would be shorter than expected.
B The identity of one amino acid would change.
C The amino acid sequence would remain unchanged.
D The identities of more than one amino acid would change.
Using your codon chart, determine how the following
mutations would affect the resulting protein.
threonine – alanine - phenylalanine
5’ ACGGCAUUU 3’

threonine – alanine - phenylalanine
5’ ACGGCGUUU 3’
2. The chain above represents three codons. Which of the
following changes would be expected in the amino acid chain if
the mutation shown above occurred?
F The amino acid sequence would be shorter than expected.
G The identity of one amino acid would change.
H The amino acid sequence would remain unchanged.
J The identities of more than one amino acid would change.