U3 Chapter 18: Regulation of Gene Expression Flashcards
Operons
A cluster of genes that are transcribed together to give a single messenger RNA (mRNA) molecule, which therefore encodes multiple proteins
Operator
Site on the DNA switches the operon on or off, resulting in coordinate regulation of the genes
Repressor
Protein that attaches to the operator in which shuts off transcription
- encoded by a separate regulatory gene
- in a repressible operon (usually encoding anabolic enzymes), repressor is active when bound to a corepressor often on the end product of the pathway
- in a inducible operon (usually encoding catabolic enzymes), binding of an inducer to an innately active repressor inactivates the repressor and turns of transcription
Activator Protein
(such as CRP, when activated by cyclic AMP, binds to a site within the promoter and stimulates transcription
Differentiation
Becoming specialized in a structure and function for their determined fate
Morphogenesis
Encompasses the processes that give shape to the organism and its various structures
Cytoplasmic Determinants
ion the unfertilized egg are distributed differentially to daughter cells, where they regulate the expression of those cells developmental fates
Induction
Signaling molecules from embryonic cells cause transcriptional changes in target cells
Pattern Formation
The development of a spatial organization of tissues and organs, begins int he early embryo
Positional Information
The molecular cues that control pattern formation, tells a cell its location relative to the body’s axes and to other cells
Proto-Oncogenes + Tumor-Suppressor Genes
A gene involved in normal cell growth
- products control cell division
- a DNA change that makes a proto-oncogene overly active converts it into an oncogene, which may promote extra cell division and cancer
- ex. Ras (a G protein) may function as an oncogene protein
