BIO 108 L5 - The prokaryotes Bacteri and Archea

What are prokaryotes involve

Bacteria and archea

what do Prokayrotes lack

lack membrane bound nucleas to host chromosomes. (befor enucleas was evolved).

why can we have a much bigger size.

Due to nuclar bound around membrane (nucleas) doe not have anythignto seperate the chromoses to nucleaus for prokayotes.

explain what a plasma memebrane is

Cell membranes and cell wall are important. it has a cytoplasm within the wall and has a selectily permeable wall.

why does it have to be selectrivly permeable

Prokaryotic cells need food sources, oxygen, protein. amny microbes need oxygen due to being anerobic. Anti biotics and toxins are stuff they do not want to go in to protect cytoplasm.

what does cell wall determine

Cell wall determs the shape of the cell. It protects the cytoplams form osmotic cells such as water or even losing water so osmosis is cruitial. We can devide bacteria into two groups

How can we divide bactera

Gram positive and negititive. based on cell wall sturucture.

Gram positive

thick wall made of piptodeclycan. when stainied these are purple due to curstol violet in the cell wall. stain more dark purple.

Gram negitive

Have thin wall made of piptodeclycan. not much crystol violet. and is Pink after staining process.

how do we deffientialt the 3 domains.

what are membrane enclosed organnels

such as midochondir or chloroplast

Introns

non coding parts of genes.

Circular chromomes.

Bacteria, Archea

Growth of temp above 100 degrees

Archea have some.

Bioflims in bacteria

organised microbial comunity encased in extra cellular polymeric susbtance and associated with surfaces.

Pros and cons of Biofilms

• nutritional value their are orgniams that can degrade cellusose and a metobolic independency. where one neutricin that isnt that important for one might be important for another (cind trophy)

• Protection- predation thinks like prodazoa like large eukaryotic orgnaims.

  • anitmigrobials such as chemicals produced form other oganims. help organims from dieing out

Prokayotic metabolism

Bob tail squid that live in hawaii.

how does this explain about prokayotic metabolism

they form relationship between a biolument bacterium known as vibrio fisheri.

how is it when a kid

does not have bacteria as a squid kid. but is exposed to allot of bacteria. immeditly exposed to wide diversity of bacteria in sea water. Only vibro fisheri manage to clonise into the quid even if thir is a snall amount of it in the see.

what is this process called.

Symbiont reruitment.

How does it occur

Cillia on squid surface beat withing 20s of hatching to draw bacterial cells.

mucus released from squid in response to peptidyglican causing chemical signals between the squid and bacterium leads vibro fisheri dominance within hours

Major changes in squid gene expresion occur after contact with only 5 V fisheri cells.

once V fisheri cells colonisation occurs morphology of squid changes 9the opening of closing of ducts) prevents colonisation of other microbes.

What else can the do to reverse the bio illuminence

because they have excusite study system they can remove symbions from ight organs and can open ducts to allow the recruitment of vibrio fisheri to happen.

What happens vibro fisehri bug is not present.

will not gain bio illuminence so these bgs are curital for the survival for squids in hiwaii.

how does it act

in day doesnt need light. the symboint conc is low but increases. by night the density is at ta high so it can do iolumence to mimic tand stop showing shadow and cloking mooon light. other preditors aremimiced. at the end of night it doesnt want the v fisheri to have all these bacteri and release 95% of these bacteria through ducts. Then it leaves 5% of these bugs to help for tmrw.

Quorum sensing

bacteria won’t do anything/express phenotype until certain density. so that bmeans biolumeneces only expressed in high concentration.

how does it work

For cells wich are bacteria they have a single inducer protein which releases molecules into the environemnt. Once there is a high accumulation of the vibrio fisheri molecules in the enviornment the bacteria has a signal receptor protein which fits like a lock and key with the molecule. THe infomraiton comes into the cells and tells cells to turn on the collectuve behaviour of turing on the light. The only way for the ligh to be emit is for all bacteria cells to work in unison.

each molecule will lock and key with a receptor that is similer to their strucure. No other molecule will be able to do lock and key with the receptor.

examples of phynotypic expression of quarum sensing

biolumenese, biofilm, exoenzyme production,

importance of quarum sensing mecically

contact lenses, cyctic firosis in lungs.