LIFE 120 Lecture Notes - Lecture 35: Cyclic Adenosine Monophosphate, Ion, Allolactose
Document Summary
Chapter 15 lecture 1 with clicker questions in red. Overview: differential expression of genes: 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: regulation happens at different stages, rna molecules play many roles in regulating gene expression in eukaryotes. Bacteria: bacteria respond to environmental change by regulating transcription, natural selection has favored bacteria that produce only the gene products needed by the cell. Production of only necessary enzymes needed at the moment: cells regulate enzyme production in two ways feedback inhibition rapid (cid:862)shut dow(cid:374)(cid:863) of (cid:271)iosy(cid:374)thesis, gene regulation. Prolo(cid:374)ged (cid:862)tur(cid:374) o(cid:374) or tur(cid:374) off(cid:863) a pathway. 5 genes in tryptophan operon (trp operon) Coordinated by a single on-off (cid:862)swit(cid:272)h(cid:863) operator transcribed as a single mrna from 1 promoter. For example, e. coli can synthesize the amino acid tryptophan.
