helps conserve E and resources

does not waste E on producing uneeded things

2 major levels of regulation in cells

1. post translational

2. pre-existing enzymes

1. transcriptional reg- DNA binding proteins, prevent unneeded protein

2. translational reg

3. post translational regulation

**DNA binding protein- prevens uneeded protein

*Proteins binding and it's specificity assist in regulation.

specificities comes from- grooves on protein binding sites of DNA- homodimeric proteins

major groove

inverted repeat

<!-- /* Font Definitions */ @font-face {font-family:Arial; panose-1:2 11 6 4 2 2 2 2 2 4; mso-font-charset:0; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:3 0 0 0 1 0;} @font-face {font-family:Arial; panose-1:2 11 6 4 2 2 2 2 2 4; mso-font-charset:0; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:3 0 0 0 1 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:"Times New Roman";} .MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; font-size:10.0pt; mso-ansi-font-size:10.0pt; mso-bidi-font-size:10.0pt;} @page WordSection1 {size:8.5in 11.0in; margin:1.0in 1.25in 1.0in 1.25in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.WordSection1 {page:WordSection1;} --> Homodimeric proteins**

DNA is main site of protein binding

inverted repeat- are binding site for regulatory proteins

Homodimeric proteins- proteins composed of 2 identical polypeptides. dimers interact with inverted repeats ON DNA, each polypeptide binds to ONE inverted

which out of

post- translation

translation

or transcription has the fastest gene regu

example of arg.

when too much arg in body what does cell do?

in the absense of arg, cel produces the lacking, when too much arg, ARG binds to REPRESSOR, creating a block so that RNA polymerase is unabe to pass on mRNa preventing transcription

think about a negative person bring back to earth someone who is too euthsiastic--> creates a barrier

repressor is inactive when not enough arg

excess Argine acts as a copreesor binding to repressor causing blockage of polymerase

mechnanism of repression and induction

(how can inducers and corepressors affet transcription)

bind to ALLOSTERIC REPRESSOR PROTEIN (feed back inhibition), allosteric repressor becomes active and binds to region of DNA near promoter called OPERATOR

-->

***Transcription is physically blocked when repressor binds to operator

* in the basent of arg--> repressor is inacive, no need for it

*in the pressence of arg- arg binds to presspressor creating BLOCK so that RNA polymeras is unable to pass on mRNA (reducing amount of transcription)

ARG pressence: binds to repressor, goes to operator, BLOCKS TRANSCRIPTION

production of an enzyme in response to a signal 

opposite from repression, enzyme is only made when when substrate is present , more of a catabolic enzyme 

inducer substance that induces enzyme synthesis

corepressor- substance the represses enzyme synthesis

this all deals with enzyme synthesis called effectors 

at the initial state repressor is blocking lactose from producing more stubstrates

inorder to produce more inducer attaches to current lac operator repressor site moving it out of the way in order to synthesize more lactose 

feedback inhibition 

or negative control 

What is positive control. How does it function?

what are involved??

regulate protein activity, the binding of RNA polymerase to DNA 

1. activator protein

2. RNA poly

3. activator binding sites

1. Activator proteins assist RNA polymerase in recognize

promoter by binding to "activiator binding sites" NOT operator!

negative control 

repressor is in negative 

sensor kinase

response regulator 

response regulator

sensor kinases is like it sounds it SENSES enviromental signal

response regulator- dna binding protein that regulates transcription 

P. Aaeruginosa- switches from free living to growing as biofilm

S. aureus

MAINLY IN ARCHAEA domain 

define stringent reponse

what domain is it specific to 

global control mechanism triggered by amino acid starvation 

BACTERIA ONLYYY!!!!

swarmer cells

stalked cells 

reproductive role 

stalkers want to reproduced by force =(

OBSTRUCT translation

-inhibit translation of COMPLETEMENTARY mRNA by base pairing to it--> obstructing translation

function of riboswitches 

specific's to how

RNA domains in an mRNA molecule that can bind small molecules to control translation of mRNA 

- does not allow recognition of shine dog sequence--> no recognition of ribosomes in prok--> ineffect; no protein synthesis

bacteria fungi, and plants

almost everything but us and bacteria 

they are regulatory RNA molecules that bind to mRNA which causes stoppage of transcription

1. attenuation,  what is it's function

2. attenuation tryptophen is only found in which domain?

attenuation is a transcriptional control mechanism that functions by premature termination of mRNA synthesis

2. prokaryotes ONLY

tryptophan acts as a negative control mechanisms inhibiting transcription in prokaryotes ONLY!!

READ is it NOT in prok, or ONLY in pro?????

multiple operons, controlled by same regul protein

referring to postive control and it's ability to maniupulate protein synthesis by binding proteins that interact directly with DNA