Chapter 16 AP Bio Flashcards

Control of Gene Expression

318832416	positive control	increases the frequency of initiation
318832417	negative control	decreases the frequency of initiation
318832418	repressors	proteins that mediate negative control that bind to operators
318832419	operators	regulatory sites on DNA
318832420	activators	regulatory, alosteric proteins that mediate positive control
318832421	lac operon	consists of a promoter, an operator and 3 genes that encode protein required for the metabolism of lactose
318832422	trp operon	encodes the enzymes necessary to synthesize tryptophan
318832423	induction	when enzymes for a certain pathway are produced in response to a substrate
318832424	repression	when bacteria capable of making biosynthetic enzymes don't produce them
318832425	catabolic pathways	breakdown molecules
318832426	anabolic pathways	build up molecules
318965664	regulatory proteins	modulate the ability of RNA polymerase to bind to the promoter
318965665	homeostasis	metabolic equilibrium actively maintained by several complex biological mechanisms that operate via the autonomic nervous system to offset disrupting changes
318965666	apoptosis	programmed cell death
318965667	major groove	Larger groove that spirals around the DNA double helix. Provides a location where a protein can bind to a particular sequence of bases and affect the expression of a gene.
318965668	DNA-binding motifs	a region found in a regulatory protein that is capable of binding to a specific base sequence in DNA
318965669	helix turn helix	dna binding motif which has two alpha helices connected by a turn
318965670	recognition helix	recognizes and makes contact with a base sequence along the major groove of DNA Hydrogen bonding between an α-helix and nucleotide bases is one way a transcription factor can bind to DNA
318965671	homeodomain motif	a special class of helix turn helix motifs found in regulatory proteins that control development in eukaryotes
318965672	homeodomain	60 amino acid protein, binds to DNA and regulates expression
318965673	zinc finger motif	A type of DNA-binding motif in regulatory proteins that incorporates zinc atoms in its structure.
318965674	leucine zipper motif	A motif in regulatory proteins in which two different protein subunits associate to form a single DNA-binding site; the proteins are connected by an association between hydrophobic regions containing leucines (the "zipper").
318965675	derepressed	when tryptophan levels fall and the repressor alone cannot bind to the operator, allowing expression of the operon
318965676	general transcription factors	any of a group of transcription factors necessary for the formation of an initiation complex by RNA polymerase II at a promoter. This allows a basal level that can be increased by the action of specific factors
318965677	specific transcription factors	any of a great number of transcription factors that act in a time- or tissue-dependent manner to increase DNA transcription above the basal level
318965678	enhancers	a site of regulatory protein binding on the DNA molecule distant from the promoter and start site for a gene's transcription
318965679	coactivators and mediators	link transcription factors to RNA polymerase II
318965680	transcription complex	the whole complex of transcription factors and RNA polymerase II bound to the promoter
318965681	transcription activators	some of theses alter chormatin structure
318965682	histone	protein molecule around which DNA is tightly coiled in chromatin
318965683	chromatin-remodeling complexes	use energy from ATP to alter chromatin structure
318965684	mRNA	must be transported out of the nucleus for translation
318965685	translation repressor proteins	shut down translation by binding to the beginning of the transcript so that it cannot attach to the ribosome
318965686	proteases	enzymes that degrade proteins by breaking peptide bonds, converting a protein into its constituent amino acids
318965687	ubiquitin	Small protein that is linked to other proteins as a way of marking the targeted protein for degradation by proteasomes.
318965688	proteasome	a cellular organelle that degrades proteins marked with ubiquitin