describe - gene alteration

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Describe: gene alteration b.stev

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miscoded mRNA, mRNA mutations, frameshift mutation, base-pair substitutions, missense mutation, nonsense mutation, silent mutation, mutagens, uv light mutagen, nitrous acid mutagen, base analog mutagens

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Page 1: Describe - Gene Alteration

Describe: gene alteration

b.stev

Page 2: Describe - Gene Alteration

chromosomes may alter abnormally - this is said to be a: mutation> It causes miscoded mRNAmRNA codes for proteins that gives

functions to the bacteria’s processes,

thus alteration to this changes how the

bacteria can operate correctlysome have little effect/ others, contained within codons that would aid survival of the bacteria: - defence toxin production against competition - digestion enzyme change to the environmentOR various purposes that effects their abilities

(Campbell N. A, Reece J. B, 2005)

Page 3: Describe - Gene Alteration

A U G A A G U U U G G U U A A

Met Lys Phe Gly STOP

U instead of a CGlyGly CODONS CODONS:

GGU GGC GGA GGG

Page 4: Describe - Gene Alteration

MISSENSE MUTATION:

makes an amino acid,though the specific amino acid that was wanted within the sequence of the mRNAhas changed

A U G A A G U U U A G U U A A

Met Lys Phe Ser STOP

A instead of a G change in

the amino acidamino acid

Page 5: Describe - Gene Alteration

NONSENSE MUTATION:

codon changeschanges to the codes for a STOP codon

Results: a shorter protein is made that is usually non-functional to the bacteria

A U G U A G U U U G G U U A A

Met STOP

U instead of A

(Campbell N. A, Reece J. B, 2005)

Page 6: Describe - Gene Alteration

HAS a disastrous effect as it causes the sequence to become,’out of lineout of line,’ & as such results in extensive missense mutationsRESULTS:

proteins that are probably non-functional and/ or prematurely terminate in sequence

INSERTION/ DELETION OF PAIRS

Page 7: Describe - Gene Alteration

A U G A A G U U U G G U U A A

Met Lys Phe Gly STOP

A G

INTENDED SEQUENCE

insertion

Page 8: Describe - Gene Alteration

mutagens

UV light- causes thymine dimers in chemical bonding:

DNA

RESULTS: inability to insert correct bases

when

transcribed in process to the

mRNANOTE: this is how UV lightcan be used to kill bacteria

Chemical OR Physical agent that causes a mutation

(Pommerville J.C, 2004)

Page 9: Describe - Gene Alteration

A C A A C C

T G T T G G normal DNA

A C A A C CT G T T G G

abnormal DNA

UV light: chemical bonding change

Page 10: Describe - Gene Alteration

Nitrous acidTHE [A]:adenine base; in

DNA

converts into a

hypoxanthinehypoxanthine molecule(s)RESULTS:no existance of an, [A-T] pairinstead; [hypoxantine&hypoxantine& C] pair entire purpose is thereafter

altered

Page 11: Describe - Gene Alteration

o CHEMICAL structure is similar

o resembles the bases of DNA

Replaces the, [ T ]: thymine base; DNA

AGAIN – entire purpose is then

altered

Base analog

ie: chemical, 5-bromouracil

Page 12: Describe - Gene Alteration

other chemicals effect DNA in some way

ie: benzopyrene (in soot) aflatoxin heavy smoke

Different effects

(Pommerville J.C, 2004)

Page 13: Describe - Gene Alteration

Bibliography

Campbell N. A, Reece J. B. (2005). Biology (7th ed.). San Francisco: Benjamin Cummings

Pommerville J.C. (2004). Alcamo’s – Fundamentals of Microbiology (7th ed.). Massachusetts: Jones and Bartlett.