one gene - one protein? (1 Viewer)

[roosterman]

could someone please explain in simple terms what this means?

and why beadle and tatums experiment made the hyptothesis change to one gene - one polypeptide?


Cheers.

 

[Irskin]

The one gene - one protein hypothesis simply means that each gene on our chromosomes is controlled by a specific protein. Without this protein (or enzyme) the gene would not function properly.

This was demonstrated by Beadle and Tatum when they showed that bread mould after being exposed to X-rays, did not contain the usual genes because of nutritional defeciencies (mutations) had affected it's proteins. The hypothesis was changed to 'one gene - one polypeptide' because not all proteins are enzymes (eg haemoglobin) and do not affect our genetic composition. Also, some proteins contain more than one polypeptide, so this is a more correct arguement