: Use the following words to fill in the blanks: transcription, dairy products, enzymes, proteins, repressor, rna polymerase, lactose intolerant, lactase, operator, ecoli, transcribe, bases, repressor, operator

An example of prokaryotic gene expression is the lac operon. When a person is 1), they do not produce the enzyme 2), which aids in the digestion of lactose, the sugar found in 3). If a person who is lactose intolerant eats or drinks a dairy product, lactose travels down the digestive tract into the large intestine, where the genes in the bacteria, 4) , are turned on to create the 5) / 6) needed to digest the lactose. In E. Coli, when lactose is present, it acts as an inducer and binds to the 7) protein, keeping it from attaching to the 8). 9) then is able to attach to and 10) the E. Coli gene by matching up the 11). When lactose is NOT present, the 12) protein binds to the 13 and transcription is blocked. This is an example of gene expression (production of proteins) being controlled at 14).