BIOL 1105 Lecture Notes - Lecture 14: Intron, Proteasome, Chromatin
Document Summary
Gene expression- process of converting genetic information in the form of a gene into a gene product, usually an active protein. Prokaryotes regulate gene expression in response to environmental changes (changes quickly) Eukaryotes regulate gene expression for development and to maintain homeostasis (occur slowly) Provides first opportunity for cells to do gene expression. Most common in both eukaryotes and prokaryotes (especially prokaryotes) A promoter region consists of regulatory dna sequence upstream and from transcription start site. Rna polymerase binds to the core promoter to initiate transcription. Regulatory proteins may affect the ability of rna polymerase to bind to the promoter. In eukaryotes, each gene has its own promoter sequence. In prokaryotes, several genes can be controlled by a single promoter. Positive control is when a activator protein promote the transcription of a gene. Negative control occurs when a repressor protein prevents the dna to be transcribed. Activator binding site- may be close to the core promoter or further away.