ch 18-20

a unit of genetic unction found in bacteria ad phages, consisting of a promoter, an operator, and a coordinately regulated cluster of genes whose products function in a common pathway

in bac DNA, a sequence of nucleotides near the start of an operon to which an active repressor can attach; the binding of the repressor prevents RNA pol from attaching to the promter and transcribing the genes of the operon

a protein that inhibits gene transcription; in prok, repressors bind to the DNA in or near the promter; in euk, they may bind to control elements within enhancers, to activators or to other proteins in a way that blocks activators from binding to DNA

a gene that codes for a protein, such as a repressor, that controls the transcription of another gene or group of genes

a small molecule that cooperates with a repressor protein to switch an operon off

The trp operon is said to be a __ because its transcription is usually on but can be inhibited when a specific small molecule binds allosterically to a regulatory protien

An ___ is usually off but can be stimulated when a specificsmall molecule interacts with a regulatory protein

a specific smal molecule that binds to a bac repressor protein and changes the repressors shape so that it cannot bind to an operator, thus switching the operator on

Enzymes in lctose pathways are __ because their synthesis is induced by a chem signal

__ generally funciton in anabolic pathways; suspend production of an end product when it is already present in sufficient quantity

small organic moleucle that accumulates when glucose is scarce

a protein that binds to DNA and stimulates gene transcription; in prok, it binds in or near the promoter; in euk, they bind to control elements in enhancers

expression of dif sets of gtenes by cells with the same genome

attachment of acetyl groups to certain amino acids of histone proteins

hypothesis that proposes that speciic combos of modifications rather than the overall level of histone acetylation help determine the chromatin config, which in turn influences transcription

process bvy which expression of either the mama or papa allele of particular genes at the start of development occurs

inheritance of traits transmitted by mechanisms not directly involving the nucleotide sequence of a genome

a segment of noncoding DNA that heps regulate trans of a genen by binding a transc factor; multiple are present in a euk gene's enhancer

transcription factors that are essential for the transc of all protein coding genes

high levels of trans of part genes at the approp time and place depend on interaction of control element with another se tof proteins which can be thought of as __

some control elements close to the promoter

control elements far from the promoter

a segment of euk DNA containing multiple control elements, usually located far from teh gene whose transcription it regulates

protein-mediated bending of dDNA is thought to bring the bound activators in contact wtih __, which in turn interact with proteins at the promoter

phenomenon by which repressors recruit proteins that deacetylate histones leading to reduced transcription

process by which different mRNA molecules are produced by the same primary transcript depending on whihc RNA segments are treated as exons and which as introns

a giant protein complex that recognizes and destroys proteins tagged for elemination by the small protein ubiquitin

a small, single stranded RNA mol generated by cellular machinery from a long doble stranded RNA molecule; associates with one or more proteins in a complex that can degrade or prevent translation of an mRNA with a comp sequence; some cases it can block transcription by proomoting chromatin modification

a technique used to silence the expression of selected genes; uses synthetic double stranded rna moelucels that match the sequence of a particular gene to trigger the breakdown of the gene's mRNA

a small, single stranded RNA molecule,, generated from a hairpin structure on a precursor RNA transcribed from a part gene; associates with one or more proeins in a complex that can degrade or prevent translation of an mRNA with a complementary sequence

structrural and functional divergence of cells as they become specialized during amulticellular organims development; depends on the control of gene expression

a maternal substane such as a protein or RNA placed into an egg that influences the course of early developmenet by regulationg the expression of genes that affect the developmental fate of cells

progressive restriction of developmental potential in which the possible fate of each cell becomes more limited as an embryo develops; at end of it, a cell is committed to its fate

a gene that helps control the orientation polarity of the egg

any of the master regulatory genes that control placement and spatial organization of body parts in animals, plants and fungi by controlling the developmental fate of groups of cells

process in which one group of embryonic cells influences developmenmt of another usually by causing changes in gene experession

a gene that, when mutant in mother , results in a mutant phenotype in offspring regardless of offsprings genotype

a substance that provides positional information in form of a concentration gradiaent along an embryonic axis

the development of body shape and organization

gene found in viral or cellula genomes that is involved in triggeringmoleuclar events that can lead to cancer

tumore suppressor gene that codes for a specific transcription factor that promotes the synthesis of cell cycle-inhibing proteins

a normal cellular gene that controls cell division and development

a gene that codes for RAs, a G protein that relays a growth signal from a growth factor receptor on plasma memrane to a cascade of protein kinases, ultimately resulting in stimulation of the cell cycle

gene whose protein product inhibits cell division, thereby preventing the uncontrolled cell growth that contributes to cancer

moleacular cues that control pattern formation in an animal or plant embryonic structure by indicating a cell's loaction relative to the organisms body axes; these cues elicit a response by genes that regulate development

development of a multicellular organism's spatial organization, the arrangement of organs and tissues in their characteristic places in three dimensional space

a maternal effect gene that codes for a protein responsible for specifiying anterior end Drosophila

genes whose protein products commit cells to becoming something, like skeletal muscle

organisms overall 3D arrangement

a mutation with a phenotype leading to death of an embryo or larva

hypthesis which proposes that gradients of substances called morphogens establish an embryo's axes and other features of its form

a technique for amplifying DNA in vitro by incubating it with specific primers, a heat-resistent DNA pol, and nucleotides

an endonuclease that recognizes and cuts DNA moleucles foreign to a bacterium; cuts at specific nucleotide sequences

DNA segment that results fromt eh cutting of DNA by a restriction enzyme

a double stranded DNA moleucle made in vitro using mRNA as a template and the enzymes reverse transcriptase and DNA pol; it corresponds to the exons of a gene

technique for separing nucleic acids or proteins on the basis of their size and electrical charge, both of whicha ffect their rate of movement through an electrical field in a gel

method to detgect and measure the expression of thousands of genes at one time; timy amounts of a large number of single-stranded DNA fragments representing different genes are fixed to a glass slide and tested for hybridization with samples of labeled cDNA

process of manipulating genes and genomes

process of manipulating organisms or their components for the purpose of making useful products

dna that has been artificially made, using DNA from diferent sources and often different species

process by which scientists can produce multiple copies of specific segments of DNA that they can then work with in the lab

used to cut strands of DNA at specific locations; derived from bacteria