Dna Mutations

1. DNA DNA
MUTATIONSMUTATIONS
BYBY
SARA KANWAL SARA KANWAL
BS-MT 3BS-MT 3
RDRD
YEAR 6 YEAR 6
THTH

SEMESTERSEMESTER

2. CONTENTS:CONTENTS:
•DNADNA
•DNA MUTATIONDNA MUTATION
•TYPESTYPES
•CLASSIFICATIONCLASSIFICATION

3. DNA: (deoxyribo nucleic DNA: (deoxyribo nucleic
acid)acid)
DNA is a DOUBLE HELICAL
structure consist of
DEOXYRIBOSE SUGAR and
FOUR NITROGEN BASES.
Four bases :
•Adenine
•Guanine
•Thiamine
•cytosine

4. DNA MUTATIONSDNA MUTATIONS :
Mutation is a permanent change in the
DNA.
•Mutations in germ cells are
transmissible.
•Mutations in somatic cells are non-
transmissible but may contribute to
change( malignant transformation)

5. TYPES OF MUTATIONS:TYPES OF MUTATIONS:
•POINT MUTATION:
•Missense mutation.
•Silent mutation.
•Non-sense mutation.
•FRAME-SHIFT MUTATION:
9.Insertion
10.Deletion
11.inversion

6. POINT MUTATIONS:POINT MUTATIONS:
Point mutations are the single-
based mutations. ( a change in
one nucleotide of the sequence)

7. CLASSIFICATION OF POINT CLASSIFICATION OF POINT
MUTATIONMUTATION:
•Missence
mutation
•Silent mutation
•Non-sense
mutation

8. MISSENSE MUTATION:MISSENSE MUTATION:
•The new codon causes an
incorrect AMINO ACID to be
inserted into the protein.
•This effect on the function of the
protein depend on what is
inserted in place of normal amino
acid.

10. NON-SENSE MUTATION:NON-SENSE MUTATION:
The new codon causes the protein
to prematurely TERMINATE,
producing a product that is
shortened and often does not
function.

12. SILENT MUTATION:SILENT MUTATION:
Silent mutation does not causes
any change
in amino acid.
(Silent mutation codes for same
amino acid)

13. FRAME-SHIFT MUTATION:FRAME-SHIFT MUTATION:
Frame-shift mutation is a change
in the reading frame of DNA.

14. •The loss or gain of 1 or 2
nucleotides causes the affected
codon and all of the codons that
follow to be misread.
•This leads to a very different and
often non-functional protein
product.

16. DELETIONDELETION:
•Mutations that result in MISSING
DNA are called DELETIONS.
•Deletions can also cause frame-
shift mutation

17. For example:For example:
•ORIGINAL: ORIGINAL:
The fat cat ate
the wee rat
•DELETION:DELETION:
The fat ate the
wee rat

18. INSERTIONS:INSERTIONS:
•Mutations that result in the
addition of extra DNA are called
insertions.
• Insertions can also cause frame
shift mutations, and general
result in a nonfunctional protein.

19. For example:For example:
•ORIGINAL:ORIGINAL:
The fat cat ate
the wee rat
•INSERTION:INSERTION:
The fat cat xlv
ate the wee rat

20. INVERSIONSINVERSIONS:
•In an inversion mutation, an entire
section of DNA is reversed.
•inversions involve large regions
of a chromosome containing
several genes.

21. For example:For example:
•ORIGINAL:ORIGINAL:
The fat cat ate
the wee rat
•INVERSION:INVERSION:
The fat tar eew
eht eta tac