Inactive Tutor answered • 01/24/20
Hi Brecka S., You can pretty much fill this in just by searching "inducible operon" on Google.
But -- "inducible" generally refers to the controlling stretch of DNA for a gene (an "operon") for an enzyme involved in a complex pathway, which your body needs to transcribe ("turn on" the enzyme) in order to increase the throughput of the pathway ("make more product(s)"). There are two conceptual ways of controlling such an enzyme (since you don't want to waste body resources in making it when it is not needed!): (1) you can keep it deliberately turned off as a default state by an always-present repressor, and turn it on when needed by an inducer, such as one of the chemicals early on in the pathway, which kicks the repressor off and allows transcription to initiate -- that's an "inducible operon" (do you see why "early on" is the crucial factor here?), or (2) you can keep it deliberately turned on as a default state -- non-methylated, and so on -- and turn it off only when excessive product of the pathway (or of consequent materials caused by the products of the pathway) is detected -- that's a repressable operon.
Some general thoughts:
(1) You will learn much more detail about the control of DNA transcription; take notes in class and look up any terms you're unsure about!
(2) Control of biological processes is frequently achieved by many parallel or serially-acting mechanisms; you will learn the primary ones first, and maybe if your career takes you there, you will study some of the secondary ones. The reason the body has evolved so many control mechanisms is, first, they must be genetically encoded to be passed on, and replication eventually fails as cells senesce, so it's good to have many controls; and second, no control is perfect, so multiple controls help evade interferences to any one control process.
-- Cheers, -- Mr. d.
