Amateur Questions on How Cells 'Read' DNA

[Smurf]

So, if DNA is supposed to be the code, or language by which our body, or our cells figure out what to do where and such. I guess I'm asking how do the cells know what the DNA is saying to them? What chemical stuff is going on that let's them 'read' the DNA and act appropriately. And wouldn't they need something to read to exist to tell them how to read the DNA first?

 

[iansmith]

A better analogy would be that DNA is the blueprint for the cell. First the cell needs to transcript the information from DNA to RNA which done by a specific enzyme (RNA polymerase). This is done because proteins are reacting to a signal which will than create chai reaction that to protein binding to specific DNA region. This regulates transcription (on/off).

The cell machinery recognize RNA as the element that dictates how proteins should be made. RNA is translate to protein by ribosomal RNA. Once proteins are made, they can dictate on the cell behave. Proteins are controlling the cell behavior not DNA.

 

[quetzalcoatl9]

smurf, i think that maybe the piece your are missing is the tRNA. each tRNA recognizes the mRNA codon and matches it to a bound amino acid.

whats interesting is that the tRNA also comes from the genetic code. even more interesting are suppressor mutations, where if a single base is changed in a gene (for instance, causing the placement of stop codon instead of an amino acid, which would be disasterous for the cell) the corresponding sequence that encodes for the tRNA of that original amino acid can also undergo a mutation that changes the anticodon part of the tRNA to set things back again! thus unnatural tRNAs that "violate" the universality of the genetic code can exist as a survival mechanism.