SCIE1106 Study Guide - Centromere, Exon, Cytoskeleton
Document Summary
Gene regulation = rules and mechanisms controlling regulation of genes. Number of protein molecules produced varies from gene to gene, and in response to environment. If 2 pathways for energy production, cell will choose on that yields most energy. Satisfy needs of cell whilst avoiding wasteful synthesis. Off" = low basal level genes is common. Coupled transcription & mrna translated in translation cytoplasm. Activator binds to dna and allows transcription. Repressor protein in the cell preventing transcription. Inducer (repressor antagonist) needed to remove repressor from dna, allowing transcription initiation. Inducer changes conformation: or co- repressor binds to repressor. Allows repressor to block transcription. Regulating protein production: transcriptional control. Control when/how often a gene is transcribed. Translation initiation most important point of control for prokaryotes: rna processing control. Controlling how rna transcript is spliced/processed: translational control. Selecting which mrnas in cytoplasm are translated: post translational control. All or no genes expressed. Due to polycistronic mrna. Larger, complex molecules broken.