cont lec 11

prokaryotic examples

1. operon lac
2. tryptophan

there are 2 types of operon

1. inducible
2. suppresive

there are more. but for us, only these matter.

once the source of glucose is present, ther eis no need to make the genes (supressive)

oce the source is changed to lactose. it changes to transcribe the gene required to handle lactose

that’s why some genes are expressed and some are not

eukaryotic regulation is complex, happens are a different level