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116 Cards in this Set
- Front
- Back
Actin Filament Locations |
- Microvili (intestines) - Contractile Bundles in cytoplasm (muscles) - Leading edge of migrating cell (like filipodia) - Contractile ring in dividing cell |
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Actin Monomers Leave after ATP dissociates |
False |
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Treadmilling |
In actin filaments, at intermediate levels of free monomers, filament stays same size, monomers are added at + end more quickly than leaving, and at - end they leave more quickly than arriving, leads to moement toward plus end from minus end
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Phalloidin |
actin drug: bonds and stabilizes filament |
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Cytochalasin |
actin drug: caps filament plus end, prevents polymerization there |
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Latrunculin |
actin drug: binds actin monomers, prevents polymerization |
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Taxol |
Microtubule drug: binds and stabilizes microtubules |
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Colchicine (colcemid) & Vinblastine (vincristine) |
microtuble drug: binds tubulin dimers, prevents polymerization |
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Monomer sequestering protein |
abp: prevents polymerization Ex: profilin |
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Nucleating proteins |
abp: bind to + end, allow adding of new monomers (forming nonbranched filaments) Ex: formin |
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actin-related proteins |
abp binds to sides of existing filaments, making branched one (important in lamellipodium of migrating cell) ex: arp2-arp3 |
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Capping protein |
abp stabilizes actin. Prevents new monomers from binding, but also prevent disassembly
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severing proteins |
abp cuts proteins, makes the cell cortex more fluid, less gel like |
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Cross linking proteins |
apb mechanical support for cell membrane, makes cell cortex less fluid, more gel like |
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bundling proteins |
fillipodia or microvilli of cells |
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Myosin motor proteins |
tracks for organelle transport, contraction in muscles |
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Lamellipodia |
bigger ones, attach to ECM or to proteins on another cell due to integrins. Ones that dont attach are swept backward over cells upper surface, doing ruffling |
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Rho-GTPase Protein Family |
Actin interaction with actin binding proteins involves the activation of these (there are three of them) Rac, CDC 42, and Rho |
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Rac |
Rho-GTPase Protein Family Lamellipodia formation |
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CDC 42 |
Rho-GTPase Protein Family Fillopodia formation |
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Rho |
Rho-GTPase Protein Family Bundles of Contractile Actin |
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Myosin I |
- Present in all cells - Single head domain binds/hydrolyzes ATP, allows it to move along actin filament (head determines cargo) - Only move toward + end - Can bind to plasma membrane, moves actin filament, like during migration and cell shape change |
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Myosin II |
- only in muscles - Dimer: 2 heads and coiled coil tail of 2 heavy chains - (-) end of actin filaments overlap myosin filaments - Myosin filaments slide actin filament in opposite directions
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Myofibrils |
- Make up the bulk of muscle cytoplasm - Made of a chain of sarcomeres (the contractile unit) - Actin filaments are anchored to Z-disk structures (on either end with actin, myosin is in the middle)
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Tropomyosin and Troponin |
Tropomyosin (on Myosin II) Normally blocks myosin II binding side on actin. Troponin is attached and can bind Ca2+, causing conformational change, exposing myosin II binding site |
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Which carbon does DNA have an H instead of an OH like RNA? |
Carbon 2' |
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Purines |
- A and G |
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Pyrimidines |
- C and T |
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A and T |
form 2 H bonds |
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C and G |
form 3 H bonds |
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RNA Polymerase |
- adds ribonucleotides one by one to active site - RNA goes in through the Ribonucleoside Triphosphate Tunnel |
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Messenger RNA |
encode protein sequence |
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Ribosomal RNAs |
- form core of ribosome - catalytic roles in ribosome for protein synthesis - catalyze peptide bond formation between amino acids |
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Transfer RNAs |
adaptor between mRNA and Amino Acids |
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Micro RNA |
regulates gene expression |
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Other Noncoding RNAs (ncRNA) |
splicing, regulation of gene expression, telomere maintenance, other processes |
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Promoter Region in Bacterial DNA |
Induces RNA polymerase to bind tightly to it |
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Sigma Factor Subunit |
Attached to bacterial RNA Polymerase, recognizes promoter sequence and allows RNA polymerase to tightly bind to it |
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A terminator sequence signals RNA polymerase to stop synthesizing, and the terminator sequence is transcribed into the RNA |
True true true |
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RNA Polymerase 1 |
transcribes rRNA genes |
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RNA Polymerase 2 |
transcribes all protein genes, miRNA gnes, ncRNA genes (eg. spliceosomes) |
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RNA Polymerase 3 |
transcribes tRNA genes, 5S rRNA genes, and other small RNAs |
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TATA box |
Present on Eukaryotic promoter, upstream of +1 |
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TFIID |
Initiating transcription factor. Includes TBP (TATA binding protein) |
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TBP |
TATA Binding Protein, present on TFIID, recognizes the TATA Box and distorts the DNA there, acting as a signal for other transcription factors and RNA polymerase to assemble for transcription initiation complex |
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TFIIH |
- Unwinds DNA helix (ATP dependent) to expose template - Phophorylates RNA Polymerase 2 tail, releasing it from transcription initiation complex, beginning transcription. After transcription is done, the tail is dephosphorylated - Phosphorylation of tail also leads to assembly of RNA processing proteins on its tail |
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5' Capping |
mRNA processing in Eukaryotes. Methylated guanine is added to 5' cap after ~25 bp are made
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Polyadenylation |
mRNA processing in Eukaryotes. Poly A tail (100-600 adenines) is added near 3' end. Polyadnylation signal recruits the protein complex that cleaves the mRNA near the signal, after which poly A tail is added |
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Poly A Polymerase |
Adds the Poly A tail after the mRNA is cleaved near the signal |
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The distance between 5' end and branched sequence is usually shorter than between the 3' end and the branched sequence |
FALSE! |
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How are introns spliced out during processing? |
In eukaryotes, the 2' OH group of Adenine cleaves RNA at splice juntion. 5' Splice junction of intron covalently links to 2'OH of A, and 5' exon is release. Then 5' phosphate of exon 2 reacts with 3' OH, splices both exons and release the intron in the form of a lariat rope |
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small nuclear ribonculeoprotiens (snRNPs) |
recognize special intronic sequences that will be cut out
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U1 snRNP |
recognizes 5' end of intron |
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U2 snRNP |
recognizes 3' branch point junction
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Amino Acyl- tRNA synthetase |
One per amino acid that links amino acid to tRNA |
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Charging |
When tRNA is bound to amino acid,, this bond is high energy, will be hydrolzyes during peptide bond formation, the energy of this bond gives energy to bind amino acids together |
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translation initiation factor |
replaces the 5' cap protein in the cytosol, this can be recognized by small ribosome subunit |
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Peptidyl Transferase |
rRNA acts as this, it directs tRNA to growing polypeptide |
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Ribozymes |
RNA molecules with catalytic functions (ribosomes) |
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Initiator methionine tRNA |
slightly different than regulat tRNA< initiates protein synthesis |
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formyl-methionine |
prokaryotic translation initiator |
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Tetracyclene |
antibiotic against bacterial RNA synthesis: blocks binding of aminoacyl-tRNA to A site of ribosome |
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Streptomyocin |
antibiotic for bacterial RNA synthesis: prevents transition from initiation complex to chain elongation |
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Deamination |
removes amino group from cytosine to produce abberant uracil |
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semiconservative replication model |
each strand is replicated and bound to new one, one new strand, one original in each double helix |
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dispersive replication model |
parts cross, no unwinding necessary |
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conservative replication model |
original helix unwinds, copies, and rewinds |
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Nucleoside |
base and sugar |
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nucleotide |
nucleoside triphsophate (so before nucleoside is hydrolyzed and bound) |
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RNA polymerase primase |
intiates synthesis on DNA, makes an RNA primer |
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RNA Primer |
About 10 nucleotides long, make by RNA polymerase primase, DNA polymerase can now add nucleotides to 3' end of primer |
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RNAse H |
recognizes RNA bound to DNA (an RNA prime) RNAse then digests it |
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Repair DNA polymerase |
replaces RNA primer after RNAse H recognizes it and RNAse digests it |
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DNA ligase |
seals nicks between replicated fragments |
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Single-stranded DNA binding protein |
keeps DNA helix unzipped |
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Primase |
synthesizes RNA prime |
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Sliding clamp |
keeps DNA polymerase on DNA strand |
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Clamp Loader |
Loads sliding clamp onto DNA polymerase |
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DNA topoisomerase |
nicks helix on single strand to relieve torsional stress from helicase unwinding strand while it is attached to proteins in the nucleus |
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Depurination |
Removes base from phosphate and sugar, but leaves backbone. If left unrepaired, you may have a deletion in the sequence. Doesn't cause strand break, though |
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Dimer Formation |
Thymine forms a dimer, which is bulky. Caused by UV radiation usually? |
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DNA Glycosylases |
recognizes mismatches, removes thei nccorect base and leaves apurinic/apyrimidinc site. |
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AP endonuclease |
recruited by absence of base, cuts phophate backbone so the repair DNA polymerase can fill in the missing nucelotide(s) using good strand as a template |
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Nonhomologous End Joining |
accidental DNA breaks. Nuclease eats some of DNA around break, and DNa ligase reseals it. (loses some of info- some nucleotides) |
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Homologous Recombination |
Strand invasion occurs, when homologous pairs are together and can use the other as a template |
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Finn Dorset Sheep |
Where the mammory cell came from |
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Scottish Blackface Sheep |
What the cell was grown inside of |
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Major Groove |
Where transcription factors that recognize regulatory DNA sequences bind to. They also bind as dimers |
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Operon |
sequence of bacterial DNA used to regulate synthesis of different proteins. |
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Operator |
DNA sequence bound by a repressor. Inside of an operon |
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Eukaryotic Transcription is regulated by enhancer sequences that act from a distance |
blah yes |
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Eukaryotic Activator Protein |
binds to enhancer on Eukaryotic DNA, can fold DNA in loop to react with mediator, promotes assembly of transcription complex
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Mediator |
Aids in transcription regulation, is connected to general transcription gactors (TATA bp, TFIID, TFIIH) |
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Repressor elements |
Prevent assembly of transcription complex |
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Histone H1 |
Binds to linker DNA losely |
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Histone Acetyltransferase |
acetylates histone tails, taking away the lysine's positive charge, weakens attraction between histone tails and DNA |
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Chromatic Remodeling Complex |
Can remodel chromatin for easier access to TATA box, also weakens interactions of DNA and histones |
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Histone Deacetylases |
Deacetylates the histone tails, increases attraction of histones and DNA, makes transcription more difficult |
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Bicoid |
Activator for EVE |
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Hunchback |
Activator for EVE |
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Giant |
Repressor for EVE (anterior end) |
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Kruppel |
Repressor for EVE (posterior end) |
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Heterochromatin |
inactive chromatin, not really transcribed |
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Euchromatin |
expressed, active part of chromatin |
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"Master" transcription regulator |
Can trigger several genes at once for transcription of all genes to produce full organ! ex: Eyeless |
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Maintenance Methyltransferase |
Recognizes methylated cytosine on one side of DNA, will methylate cytosine on other side to match |
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De Novo Methyltransferase |
methylates DNA from scratch, until maintenance one |
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Activating Marks |
acetylation of lysine residues to weaken attraction to histones or methylation of certain lysine residues (can be inherited from mother cell) |
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Represeive Marks |
Methylation of other lysine residues to tighten interactions (can be inherited from mother cell) |
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Induced Pluripotent Stem Cell (iPSC) |
reprogrammed somatic cells to embryonic stem cells (with genes Sox2, Oct4, Nanog, Klf4 (Kruppel-Like Factor) |
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Dicer |
cleaves precurose miRNA to form double stranded mRNA intermediate (~22 nucleotide pair) RISC protein complex now recognizes mature miRNA, and will attach to one strand of it and make it search for complementary target mRNA sequences |
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RISC |
protein complex that recognizes the mature miRNA and will attach to the single strand of the miRNA, to search for complementary target mRNA sequences. |
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siRNAs |
small interfering RNAs, act as a cellular defense against double stranded RNA viruses |
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Autocrine Signaling |
Signal acts on the same cell it came from (eg. stem cells) |
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Synaptic Signaling |
Can be over long distances if the axon in long, but it only really travels across a synapse |
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Contact- Dependent Signaling |
direct contact between cells is needed. A cell will have a surface protein recognized by receptors on adjacent cells (leads to Lateral Inhibition/ Lateral Specification) |