BIOL 1201 : Biology 1201 Exam 4 Study Guide And Notes
Document Summary
Prokaryotes and eukaryotes alter gene expression in response to their changing environment. In multicellular eukaryotes, gene expression regulates development and is responsible for differences in cell types. Rna molecules play many roles in regulating gene expression in eukaryotes. Natural selection has favored bacteria that produce only the products needed by that cell. Cell can regulate the production of enzymes by feedback inhibition or by gene regulation. Gene expression in bacteria is controlled by the operon model. Cluster of functionally related genes can be under coordinated control by a single on-off switch . The regulatory switch is a segment of dna called an operator usually positioned within the promoter. Operon the entire stretch of dna that includes the operator, the promoter, and the genes that they control. Repressible operon one that is usually on; binding of a repressor to the operator shuts off transcription (ex. trp operon)
