DNA to Disease: Examining phenotypic expression of DNA mutations
Dna Mutations
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Transcript of Dna Mutations
DNA DNA MUTATIONSMUTATIONS
BYBY
SARA KANWAL SARA KANWAL
BS-MT 3BS-MT 3RDRD YEAR 6 YEAR 6THTH SEMESTERSEMESTER
CONTENTS:CONTENTS:
• DNADNA• DNA MUTATIONDNA MUTATION• TYPESTYPES• CLASSIFICATIONCLASSIFICATION
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
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)
TYPES OF MUTATIONS:TYPES OF MUTATIONS:• POINT MUTATION:
1. Missense mutation.2. Silent mutation.3. Non-sense mutation.
• FRAME-SHIFT MUTATION:
1. Insertion2. Deletion3. inversion
POINT MUTATIONS:POINT MUTATIONS:
Point mutations are the single-based mutations. ( a change in
one nucleotide of the sequence)
CLASSIFICATION OF POINT CLASSIFICATION OF POINT MUTATIONMUTATION:
• Missence mutation
• Silent mutation
• Non-sense mutation
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.
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.
SILENT MUTATION:SILENT MUTATION:
Silent mutation does not causes any change
in amino acid.
(Silent mutation codes for same amino acid)
FRAME-SHIFT MUTATION:FRAME-SHIFT MUTATION:
Frame-shift mutation is a change in the reading frame of DNA.
• 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.
DELETIONDELETION:
• Mutations that result in MISSING DNA are called DELETIONS.
• Deletions can also cause frame-shift mutation
For example:For example:
• ORIGINAL: ORIGINAL:
The fat cat ate the wee rat
• DELETION:DELETION:
The fat ate the wee rat
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.
For example:For example:
• ORIGINAL:ORIGINAL:
The fat cat ate the wee rat
• INSERTION:INSERTION:
The fat cat xlv ate the wee rat
INVERSIONSINVERSIONS:• In an inversion mutation, an entire
section of DNA is reversed.
• inversions involve large regions of a chromosome containing several genes.
For example:For example:
• ORIGINAL:ORIGINAL:
The fat cat ate the wee rat
• INVERSION:INVERSION:
The fat tar eew eht eta tac