AP Biology: Chapter 18 Flashcards

6286755897	Feedback Inhibition	- The product acts as an allosteric inhibitor of the 1st enzyme in tryptophan pathway but this is wasteful production of enzymes	0
6286755898	Gene Regulation	- Don't block the enzyme's function, block transcription of genes for all enzymes in tryptophan pathway - Saves energy by not wasting it on unnecessary protein synthesis	1
6286755899	Operon	- Genes grouped together with related functions	2
6286755900	Promoter	- RNA polymerase binding site - Controls transcription of all genes in the operon - Transcribed as one unit and a single mRNA is made	3
6286755901	Operator	- DNA binding site of repressor proteins	4
6286755902	Repressor Operon	- Binds to DNA at the operator site - Blocking RNA polymerase - Blocks transcription - Similar to how a skateboard stops on a curb - ANABOLIC pathways (build) - Synthesizing end products - Cell allocates excess resources to other uses	5
6286755903	Inducible Operon	- CATABOLIC pathways (destroy) - Digesting nutrients to simpler molecules - Produce enzymes only when nutrients are available - Cell avoids making proteins that have nothing to do, allocates resources	6
6286755904	DNA Packing	- DNA coiling and folding - Degree of packing regulates transcription - No transcription, genes off - Wrapped histones - Double helix - Nucleosomes (beads on a string) - Chromatin fiber - Looped domains - Chromosome	7
6286755905	DNA Methylation	- Blocks transcription factors and genes turned off - Attachment of methyl groups to cytosine - Nearly permanent inactivation of genes - Ex: Barr body	8
6286755906	Acetylation of Histones	- Unwinds DNA - Loose histone enables transcription and genes to turn on - Attachment of COCH3 - Conformational change to histone proteins - Transcription factors have easier access to genes	9
6286755907	Transcription Initiation	- Controls regions of DNA - Promoter closely controls DNA sequence and binding of RNA polymerase/ transcription factors (base rate) - Enhancer distantly controls DNA sequences and binds to activator proteins (high rate)	10
6286755908	Post Transcriptional Control	- Alternative RNA splicing - Variable processing of exons creates a family of proteins	11
6286755909	Regulation of mRNA Degradation	- Life span of mRNA determines amount of protein synthesis	12
6286755910	RNA Interference siRNA	- Short segments of RNA - Binds to mRNA - Creates sections of double stranded mRNA - Death tag for mRNA (Degration) - Causes gene silencing - Post transcriptional control - Turns off genes because no proteins are produced	13
6286755911	Control of Translation	- Blocks initiation of translation stage - Regulatory protein attaches to the 5 end of mRNA - Prevents the attachment of ribosomal subunits and initiator tRNA - Blocks translation of mRNA protein	14
6286755912	Protein Processing and Degration	- Folding, cleaving, adding sugar groups, and targets for transport - Ubiquitin tagging and proteasome degradation	15
6286755913	Ubiquitin	- Death Tag - Marks unwanted proteins with a label - 76 amino acid polypeptide - Labeled proteins are broken down rapidly in waste disposers/proteasomes	16
6286755914	Proteasome	- Protein Degrading Machine - Waste disposer - Breaks down any proteins into 7-9 amino acid fragments - Cellular recycling	17
6286755915	A mutation that makes the regulatory gene of an inducible operon nonfunctional would result in	- continuous transcription of the operon's genes.	18
6286755916	A mutation that inactivates the regulator gene of a repressible operon in an E. coli cell would result in	- continuous transcription of the structural gene controlled by that regulator.	19
6286755917	The expression of genes can be controlled at all the following stages of protein synthesis EXCEPT:	- protein folding	20
6286755918	All of the following are post-transcriptional modifications of eukaryotic mRNA EXCEPT:	- Peptide bonds are formed	21