Regulating Eukaryotic Genes Flashcards
DNA methylation
occurs when methyl groups attach to DNA bases, thereby making it more difficult for transcription factors to transcribe the DNA – associated with long-term inactivation of genes
nucleosomes
a bundle of eight histone molecules that form tightly knit complexes
acetylation
histone molecules loosen their grip on the DNA molecule when acetyl groups attach – associated with activated transcription
methylation
occurs when methyl groups methylate histones, thereby condensing chromatin
proteasomes
“giant protein complexes that bind to protein molecules and degrade them” (Cliffs 139).
X inactivation
occurs when one pair of a female’s X chromosomes are randomly inactivated in every cell
protein-phosphorylating enzymes
initiate protein activation
spliceosomes
enzymes that splice out introns and connect exons, through RNA processing
enhancer
may be found either upstream or downstream to the regulatory gene; because of its distance from the “gene it influences, the DNA segment containing the enhancer folds in a way that can join the general transcription factors and RNA polymerase on the promoter” (Cliffs 139).
general transcription factors
“binding to the promoter region, these proteins are required by all transcription events to successfully initiate transcription by RNA polymerase” (Cliffs 139).
ubiquitin
is a protein that marks nonfunctional proteins for destruction
RNA processing
the different ways in which mRNA can be spliced allow a single gene to code for proteins that are specific to that cell
alternative RNA splicing
depending on which RNA segments are treated as exons and introns, different mRNA molecules can be produced from the same original transcript
RNAi (miRNA or siRNA)
miRNA = microRNAs siRNA = small interfering RNAs RNAi degrade an RNA strand by binding to it, and thereby can possibly block RNA translation
