Thread: Protein synthesis

How do cell's know when it is time to make a specific protein or enzyme?

Well it's a really big question. The structure of DNA and RNA plays a big role, as do a number of other proteins, substrates, and hormones.

Then there are a lot of ways transcription can be regulated.

http://en.wikipedia.org/wiki/Transcriptional_regulation

You could read up on this stuff for hours.

"A repressor is a DNA-binding protein that regulates the expression of one or more genes by binding to the operator and blocking the attachment of RNA polymerase to the promoter, thus preventing transcription of the genes. This blocking of expression is called repression."

What influences the repressor to bind to the operator?

Usually its structure makes it bind certain sequences of DNA preferentially. An inducer will often cause a structural change in the repressor that makes it dissociate from DNA.

Helix-turn-helix motifs are the one I can think of off the top of my head. It's been like 5 years since I took a biochemistry course on nucleic acids and my memory is getting foggy.
http://en.wikipedia.org/wiki/Helix-turn-helix

Thanks. I am in biochem right now and it just seems like the more I know, the less I know.

The process of building proteins is called Protein synthesis,sometimes used to refer alone to protein translation but divers frequently it refers to a multi-step process, which start with amino acid synthesis and imitation of nuclear DNA into messenger RNA, which is then used as input to translation.

thanx

nice discussion