AP BIOLOGY

Detailed explanation-1: -Allolac tose binds to the lac repressor and makes it change shape so it can no longer bind DNA. Allolactose is an example of an inducer, a small molecule that triggers expression of a gene or operon.

Detailed explanation-2: -A small molecule like trytophan, which switches a repressor into its active state, is called a corepressor. High tryptophan: The tryptophan binds to the trp repressor and causes it to change shape, converting into its active (DNA-binding) form.

Detailed explanation-3: -Function. Repressor proteins bind to the DNA strand and prevent RNA polymerase from being able to attach to the DNA and synthesize mRNA. Inducers bind to repressors, causing them to change shape and preventing them from binding to DNA. Therefore, they allow transcription, and thus gene expression, to take place.

Detailed explanation-4: -Definition. A repressor, as related to genomics, is a protein that inhibits the expression of one or more genes. The repressor protein works by binding to the promoter region of the gene(s), which prevents the production of messenger RNA (mRNA).