Been pondering this for queit a while... (1 Viewer)

[TheKing]

ok, so we all know about protein synthesis and all that...
the DNA strand in the nucleus is split in a certain place by an enzyme, the mRNA attaches etc....

my question is: What sends the enzyme out? What initiates this synthesis of proteins?

i know what happens and how proteins are made but how does the cell know when it is time??? what sends out the initial message?

 

[iambored]

this is a GUESS - hormones?

 

[TheKing]

i don't know the answer....
thats why i asked

 

[malkin86]

I guess it's noticed that the body needs more (whatever the polypeptide is used for). I think it just dissolves out, or something. selective permeability of the external membrane.

 

[t-i-m-m-y]

chemical stimulants. also depending on what the cell is doing. take embryonic development, lots of cell specialisation going on. i'm guess for my specific example---> hormones and genes selectively being expressed hehe

 

[TheKing]

um....
so how is it that this cell knows which protein is made, and what actually detects the shortage/need in the first place?

 

[mr EaZy]

You probs didnt do genetics the code broken
A kind of feedbacxk mechanism ius iused
i did bio in 2003, a sample polypeptide blocks a section of DNA
called junk DNA (90% of DNA is JUNK ) Junk means they dont make proteins but they have many purposes

The blocked piece of DNA disallows the DNA polymerase to create the enzymes needed because they are in excess or not needed.


Thids is how its done in procaryotes called operon. Eucaryontes are way more complicated. Were talk'n histamines, junk DNA, end cap DNA, DNJA Packaging etc . WHEEEW, im getting scared remembering my bio!!!

 

[TheKing]

DNA polymerase splits the whole of a pair of DNA.
i thought that during protein synthesis only part of the DNA is unzipped (only one gene) and only one gene is transcribed....
polymerase IS an enzyme
and are you talking about the cytoplasm and nucleic acids and NOT DNA being junk?

please explain further

 

[t-i-m-m-y]

i think junk dna is more correctly termed introns. those non-coding sequences of DNA that perhaps serve a regulatory role

anywayz this whole thread comees back to the idea of gene expression. will post up some diagrams from uni BIO textbook which explain it.

 

[TheKing]

that would be goood.....
thankyou

 

[mr EaZy]

..

 

[mr EaZy]

For more info, see genetics the code broken.
Ask about gene expression

 

[TheKing]

hey mr eazy i think that you've really missed the point of the question....
please spam somewhere else

 

[mr EaZy]

Well, gene expression is how genes get turned on/off. The genetics course will break it down for u.

Duuh FRED!!!