What are operons and how do they function in the transcription of protiens?

Answer 1

An operon is one transcribing unit. It's made up of a few subunits, including at least one promoter, one operator, and probably a number of codons.

The promoter is where enzymes bind to begin the transcription of the gene. The operator is where other enzymes bind to mediate the transcription, either speeding it up or slowing it down or stopping it altogether. The codons are the sequences that eventually become amino acids in the final protein. Any particular gene might have several operons, particularly if it's made up of sub-units or occasionally expresses different sequences (which is not unusual, really).

So you can see how that might a useful concept. Because an operon is a unit, you can't stop (or speed up) production without stopping all of it, and even if you do it will effect no other operons directly.

Probably the best way to picture it is as a sentance. A sentance is a unit of meaning in writing. Any particular idea (gene) may have many sentances (operon) or maybe only one. Each sentance has certain parts, and is in turn made up of words (codons) and letters (a base pair). Words randomly thrown together don't make a sentance... you have to have a capital letter (a promoter) and a period (terminator), as well as other structure. It's a bit more complex than that, though, because some operons can have several terminators, and well is being not read and so on. But it's a start, at least!

Hope that helps!

Answer 2

Operon is a group of continous genes that control transcription of mRNA, not translation of protein. However, transcription of mRNA does effect the translation of protein.
Operon usually consists of promoter region, inhibitor region and operator region. Different gene will have diferent type of operon and its mechanism is different. Only BACTERIA do have operon. E.g. Lac operon, which control lactose level in bacteria. Hope this helps.