AP Biology: Chapter 18 Flashcards
Terms : Hide Images [1]
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 |