genetika bakteri.ppt

7/25/2019 GENETIKA BAKTERI.ppt

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GENETIKA BAKTERI


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Standar Kompetensi :

Memahami pentingnya ilmu mikrobiologi, jenis dan peran

mikroorganisme di alam, persyaratan hidup yang meliputi faktor

fisik dan nutrisi, metabolisme serta genetika mikroorganisme.

Kompetensi Dasar:

Menjelaskan dasar informasi genetik pada bakteri

Indikator :

1.Membedakan materi genetik pada bakteri : Nukleoid dan

Plasmid2. Menjelaskan proses transfer materi genetik pada bakteri :

Transformasi, Transduksi dan Konjugasi.


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MT!"# :

1.Materi genetik pada bakteri : Nukleoid dan

Plasmid

2.Proses transfer $perpindahan% materi genetik pada bakteri :

a.Transformasi

b.Transduksi

&.Konjugasi


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'hat you need to kno( about geneti&s :

ll organisms ha)e *N and "N as geneti& material

ll organisms use the same nu&leotides

ll organisms repli&ate, trans&ribe and translate *N

The entire genomes $*N se+uen&es% of manyba&teria are kno(n 1--- times smaller than human

genome


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ene e/pression is &arefully &ontrolled.

0a&teria must be able to adapt to en)ironment and di)ide

+ui&kly

ome genes are &onstituti)e $al(ays e/pressed%

ome are indu&ible $only e/pressed (hen needed% e/ample:enymes that metabolie la&tose

ome are repressible $ e/pressed most of the time, but &an

be turned off% e/ample: enymes in)ol)ed in biosynthesis

These genes are organized into operons (a group of

genes expressed together)


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0a&terial eneti& #nformation is stored in :

1. 3hromosome and

2. Plasmid


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-4sually &ir&ular

53ondensed into Nu&leoid

5There is no nu&lear membrane

5"epli&ate semi &onser)ati)ely

5"epli&ation start from 6rigin of

"epli&ation $6ri% site

0a&terial 3hromosome


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-The genome is 7P86#*53hromosome sie &an )ary bet(een spe&ies

5The smallest is Mycoplasma genitalium

$9/1-;bp (ith


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P8M#* :

small &ir&le of *N that repli&ates

independently of the &hromosome.


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elf repli&ating: (orks independently from host &ell

@7olds spe&ifi& information :

5 Pro)ides information for se/ pilus and transfer

$i.e. the AB plasmid, most plasmids ha)e this

ability%

5 3an pro)ide ba&teria (ith antibioti& resistan&e

5 3an &ode any *N se+uen&e : This allo(s for the

produ&tion of gene protein produ&ts su&h as

insulin


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C&+uiring genes through gene transfer pro)ides ne(

geneti& information to mi&roorganisms, (hi&h may allo(

them to sur)i)e &hanging en)ironments.D

CThe major sour&e of )ariation (ithin a ba&terial spe&ies

is mutation.D

C#n mutations, usually only a single gene &hanges at anyone time.D

C#n &ontrast, gene transfer results in many genes being

transferred simultaneously, gi)ing the re&ipient &ell mu&h

more additional geneti& information.D


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0a&teria donEt ha)e se/ in the animalFplant sense ofse/ $i.e., mating follo(ed by re&ombination of (hole

genomes%.

#nstead, ba&teria a&+uire *N from other ba&teriathrough three distin&t me&hanisms:

1. Transformation

2. Transdu&tion>. 3onjugation


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aked! D"

'hen a ba&terial &ell lyses, it releases

its *N into the en)ironmentC#S$%#D&

The pro&ess of taking up naked *N$*N (ithout asso&iated

&ells or proteins%, and produ&e a stable geneti& &hange.

Transformation
http://en.wikipedia.org/wiki/Naked_DNAhttp://en.wikipedia.org/wiki/Naked_DNA


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5Transformation o&&urs naturally in )ery fe( genera of

ba&teria :Bacillus, Haemophilus, Neisseria, Acinetobacter,

andsome strains of Streptococcus and Staphylococcus

5 The re&ipient &ell must be in a physiologi&al

state in (hi&h it &an take up *N5it must be &ompetent

53ompeten&e: alterations in the ba&terial &ell (all that make

it permeable to large *N mole&ules

5 ome ba&teria, (hi&h are not normally

&ompetent, &an be made so in laboratory


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Origin

alT

ransfo

rmati

on

Exp

.

F.G

rith(19

28)using

pnumo

!o!!i


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"

#$-%&iat&

Tr

ansform

ation

Note that *N

is taken up

naked from

theen)ironment.


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"

#$-%&iat&

Tr

ansform

ation

$ ti' i l


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$rti'!ial(omptn!

)* El!troporation

3ompeten&e

denotes theability to take

up *N naked

from the

en)ironment.

Most ba&teria are

not naturally&ompetent but

many &an be

made artifi&ially

so.

rtifi&ially

indu&ed

&ompeten&e is

)ery important

to gene &loning.


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T"N*43T#6N

The pro&ess in (hi&h ba&terial *N is mo)ed from one

ba&terium to another by a ba&terial )irus $a ba&teriophage,&ommonly &alled a phage%.
http://en.wikipedia.org/wiki/Phagehttp://en.wikipedia.org/wiki/Phage


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G

nra

li+&

Trans&u

!tion0a&teriophages

are )iruses that

only infe&t $and

&an kill%ba&teria.


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G

nra

li+&

Trans&u

!tion


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,p!iali+&Trans&u!tion


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pro&ess in (hi&h a li)ing ba&terial &ell transfers

geneti& material through &ell5to5&ell &onta&t.

36NG4T#6N


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onu

gation

,xorF

/ilu

s


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Conjugation:

Defined:The transfer of genetic material from one

cell to another involving cell to cell contact

How its done

Plasmid:Self replicating independent strand of DNASex pilus:An appendage on a bacteria cell used fortransfer of genetic information


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onu

gation

F/lasm

i&

Trans

fr


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,lf-Transm

issil

0

/lasm

i&

"esistan&e Transfer Aa&tor

$&onjugation genes%

Notemultiple

resistan&e

genes.


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F

an&O

thr

/lasm

i&s

A plasmids en&ode genes that allo( both

their repli&ation and transfer. They are thus kno(n as elf5

Transmissible Plasmids.

There are other plasmids that &an take

ad)antage of &onjugation but donEt

en&ode the ne&essary genes. These are

non5self transmissible plasmids.

Transdu&tion is also &apable oftransferring smaller plasmids.


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" plasmids are named not for their mode of

transmission but instead for the resistan&egenes that they en&ode su&h as to antibioti&s.

ome plasmids are present in ba&teria in lo(

&opy numbers $1 or 2Fba&terium% (hereas otherplasmids are present in high &opy numbers(such

100s/bact.).

Plasmids, " and other(ise, &an ha)e )ery (ide

host ranges allo(ing easy transfer of alreadye)ol)ed genes bet(een ba&terial spe&ies.


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T1E E#"

genetika bakteri.ppt

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