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PCB 4522 Exam 3 Latest Fall/Spring Term % Guaranteed Pass
(Complete)
chromosomea are located in the nucleus Each chromosome consists of many units of replication called replicons What requires coordination of replicons for DNA production during cell cycle replication Replication is determined by complex pathways that ________ _________ _______ regulate cell cycle Series of stages that a cell goes through cell cycle What are the two phases of the cycle cell? M Phase and Interphase Which cell cycle phase includes the process mitosis and cytokinesis M phase How does the M phase work Cells divide into two new cells
How long does mitosis last in the M phase last? an hour What is the Interphase? Period between cell divisions, cells grow and engage in diverse metabolic activities How long does the interphase last? days, weeks or even longer What are the 3 steps within the Interphase? G1, S, G Where does G1 take place? between end of mitosis beginning of DNA replication What is highly regulated and controlled by a checkpoint G What is the S phase DNA replication and chromosome duplication Where does the G2 occur? between end of S and beginning of mitosis What does G2 do cell grows and preps for mitosis What does G1 do? cell growth, carries out normal metabolism; organelle dup
MreB, PBP2 and RodA Where does septum formation occur? middle of the cell 50% from septum to each end of bacterium Which rod shape protein of E.coli is important for cell wall integrity? MreB Which rod shape protein of E.coli interacts with RodA PBP Which rod shape protein of E.coli is a member of SEDS bacterial protein family RodA Which rod shape protein of E.coli catalyzes formation of crosslinks in peptidoglycan RodA What does SEDS stand for? shape, elongation, division, and sporulation Which rod shape protein of E.coli resembles eukaryotic actin protein which polymerizes to from the cytoskeletal filaments in eukaryotic cells MreB What protein is necessary for septum formation? ftsZ What protein resembles tublin and polymerizes to form a zing or septal ring?
ftsZ Where is the z-ring formed inside bacterial envelope Does fit FtsZ require help? yes, needs to recruit enzymes needed to form septum. _________ in division or segregation affect cell shape mutations Does ftsZ have long or short filaments long How does ftsZ have long filaments? septum that divides daugther bacteria fails to form Over-expression of ftsZ induces what? minicells in mutants that produce too many septa (small and lack DNA) _________ and __________ genes regulated the location of the septum min and noc/slm What are the names of the genes minB locus is consisted of? minC, - D, and - E What genes in the minB locus form a division inhibitor? Min C and Min D
How does SlmA/Noc prevent septation from occuring in space occupied by bacterial chromosome Bind to DNA & interact with FtsZ to prevent polymerization and septum formation Bacillis subtilis/NOC binds to membrane to prevent septum formation How are daughter chromosomes disentangled from each other toposiomerases When does chromosome segregation occur? concurrently with DNA replication, if it begins before DNA replication is finished Chromosomal segregation might require what? site specific recombination site-specific recombination acts on target sequence near chromosome terminus seperates daughter chromosomes site-specific recombination releases what chromosomes What are the basic elements of cell signaling? 1st messager/ ligand, receptors 1st messager/ ligand molecule that binds to receptor
receptor in target cells receieve A set of ser/thr protein kinases is called cyclin- dependent kinases What does cyclin- dependent kinases control cell cycle progression What are cyclin proteins required for? to activate cyclin-dependent kinase proteins Most information about cell cycle is mainly explored in yeast Cell cycle: START is cells committed to DNA rep, G1/S cyclins restriction point during G1 cells becomes committed to division Cell cycle: END is G2/M (mitosis cyclins) What do checkpoints do? watches out for damaged chromosomal DNA so that cell cycle occurs accurately and in proper order What are the two different types of signal transduction pathways?
_______________ __________ can serve as binding sites for proteins such as Grb/SOS phosphotyosine residues Grb/SOS are considered partners Grb2 binds to TyrP WHY? So SOS is brought to membrane and can activate inactive RAS-GDP Process of the RAS activation recruit RAF to membrane to become activated Recruitment of exchange factor SOS to the membrane is to activate what protein? RAS What is the function of Raf initiate for? phosphorylation cascade leading to phosphorylation of set of transcription factors that can enter the nucleus and begin S-phase What protein in responsible for the checkpoint control for entry into S phase? p what guardian of the cell integrity binds to activate the domains of a set essential transcription factor, (E2F family) in cytoplasm to prevent them from turning on genes required for cell cycle progression Rb What proteins are considered tumor suppressor and guardians of cell integrity
p53 & Rb What do p53 and Rb proteins do? ensure the cell side and absence of DNA damage criteria is met. p53 job relays intro to CDK/cyclins that damaged occurred to prevent entry into S-phase and to arrest cell cycle What does p53 activate? apoptosis or programmed cell death (PCB) When Rb is phosphorylayed by a cyclin/CDK complex what does it release? releases E2F to permit cell cycle progression SOS removes ______and replaces it with _____ activating _______ GDP, GTP, RAS A replicated region appears as a ________ within nonreplicated DNA. bubble A replicated fork is initiated where and moves how? at origin, sequentially along DNA When is replication unidirectional single rep fork created at origin When is replication bidirectional when origin creates 2 rep fork that move in opposite directions
oriC contains binding sites for DnaA called dnaA boxes oriC contain what kind of repeats 11 GATC/CTAG What is DnaA DNA binding is influenced by? ATP, ADP, or no nucleotide binding. What does DNA methylation control? activity of the replication origin What does replication generate hemimethylated DNA hemimethylated DNA cannnot initiate replication until what they have been restored to the fully methylated state How long is the delay before GATC/CTAG repeats are remethylated? 13 mins DNA methylation in bacteria aids in distinguishing old and new DNA strands during repair what happens When DNA polymerase makes a mistake? repair system uses the methylated strand as a template to correct errors, ensuring accurate identification of the new strand
What are requirements for initiation of replication protein synthesis (licensing factor) transcription activation, membrane/cell wall synthesis Which requirement for initiation of replication is needed to produce the origin recognition protein, DnaA, require for each round of replication Protein synthesis Which requirement for initiation of replication is necessary, involving the transcription of genes flanking oriC and aids DnaA in opening the origin? transcription activation what is considered vital for initiation of replication membrane/cell wall synthesis Initiation of replication at oriC involves 6 proteins. Those 6 proteins include? DnaA, DnaB, DnaC, HU, gyrase and SSB During initiation of replication at oriC, which protein plays a unique role in the initiation process and recognizes oriC sequences for initiation of replication DnaA During initiation of replication at oriC, which protein is an ATP dependent helicase and unwinds DNA after the origin opens, but requires full methylation of both DNA strands DnaB During initiation of replication at oriC, which protein at the origin of replication help helicase (DnaB) to recognize the site for its action DnaC
What protein can SeqA interact with? DnaA What protein is recurited to the replication origin to convert DnaA-ATP to DnaA-ADP Hda protein Eukaryotes replicate their genome in small portions called replicons replicons length 40 to 100 kb When are individual replicons activated? during S phase is replication in eukaryotes fast or slow, how many bp/min? slow, 2,000 due to chromatin structure is bacterial replication fast or slow, how many bp/min? fast, 50, Replication forks are organized into ________ in the _________ foci, nucleus The only information about initiation of replication in eukaryotic cells comes from yeast, Saccharomyces cerevisiae Origins in saccharomyces cerevisiae are short - sequences that have an essential ______ bp sequence
A-T, 11
What is the name of origin of replication in yeast? autonomous replication sequence (ARS) autonomous replication sequence (ARS) is associated with what and contains how many proteins? multiprotein complex called origin recognition complex (ORC), 6 proteins ________ factor binds to ORC licensing What are two essential licensing factors connecting ORC to replication initiation protein complex? Cdc6 and Cdt When is Cdc6 synthesized? exclusively in G1 phase Cdc6 binds to _______, enabling _______ protein binding ORC, MCM Cdt1 helps? load MCM proteins onto origins What licensing factor is synthesized exclusively in G1 phase? Cdc What licensing factor helps load MCM proteins onto origins?
True or False A bacterium or eukaryotic cell has several different DNA polymerases enzymes True Which DNA polymerase in bacteria is involved in repairing damaged DNA and has a subsidiary role in semiconservative replication DNA polymerase I Which DNA polymerase in bacteria is required for restarting a replication fork blocked by DNA damage DNA polymerase II Which DNA polymerase in bacteria is responsible for de novo synthesis of new DNA strands during replication DNA polymerase III Which DNA polymerase in bacteria is involved in allowing replication to by-pass certain types of damage and are referred to as error-prone polymerases Dna polymerases IV and V Which DNA polymerase in eukaryotic is required for nuclear replication DNA polymerases δ and ε Which DNA polymerase in eukaryotic is involved in "priming" or initiating replication DNA polymerase α Which DNA polymerase in eukaryotic what do other DNA polymerase do? roles in repairing damaged nuclear DNA
Some DNA polymerases are involved in ___________ ___________ of damaged DNA when repair is impossible translesion replication Mitochondrial DNA replication is carried out by DNA polymerase γ True or False Chloroplasts do not have their own replication system False They do DNA polymerases provide a "proofreading" error-control system A 3'-5' exonuclease activity is typically employed to do what remove bases that have been incorrectly added to DNA Which DNA polymerase removes the RNA primers at the 5′ end of each Okazaki fragment during replication and replaces them with DNA DNA polymerase I True or False DNA Polymerases have various nuclease activities True Which polymerase I fragment also known as the Klenow fragment contains both polymerase and 3′-5′ exonuclease (proofreading) activities. Large Fragment
