MBG Theoretic Notes PDF

MBG THEORETIC NOTES 2. THE CELL MEMBRANE funct!on of plasma membrane ; - protect!ve barr!e - trasportat!on (select!vely pe...

MBG THEORETIC NOTES 2. THE CELL MEMBRANE funct!on of plasma membrane ; - protect!ve barr!e - trasportat!on (select!vely pereable) - cell recogn!t!os - ancho!ng s!tes for f!laments of cytosceleton b!nd!ng s!tes for enzymes - - !nterlock!ng cells (junct!ons) - conta!ns the cytoplasm STRUCTURE Of CELL MEMBRANE f!lm of l!p!d & th!n prote!n - - held together by necovalent. !nt & dynam!c , flu!d · double layer l!p!d mol. (5nm) = l!p!d b!layer : !mpermeable to water-soluble mel. - most membrane prote!ns , spon the b!layer , med!ate funct!ons (taspe , s!s of reac)  phosphol!p!ds Glycocalyx * 2 fatty ac!d cha!ns - cell coat Por group carbohydrate r!ch zor polar = head- > : -glycend glycoprete!ns v proteoglyces v tu!n - napde : hydrophob!c membrane prote!ns 1 s!de expos!on I - 2 s!de expos!e I GPI enche !xmut!ple s!ngle ro Tovalent p! l!p!d cha!n ·ne!ovalett!n prote!ns ser!permeable small not & lage hydrophob!c ma. = -neubrene !ons , hydroph!t!c mal longer the water mal the!r & large on sun  TYPES Of TRANSPORT s!mple d!ffus!on d!ffus!on No X No X energy engy - low Pass!ve h!gh > - process = concentrat!on > - mel. have natural k!net!c energy te clonels Aquapor!ns conduct!on of water mel. : osmos!s prevents the !os & passage of. other - d!ffus!es of water = !ntegral membran pore prote!n low h!gh > - allows water more rap!dly - X !sotol!c > - equal enter ng & leav!ng - embedded !n plasma membrane hypota!c > - cytolys!s (swell and burst) (shr!nk and str!vel) hypertan!c > - plasmolys!s & abundant !n an!mal cells for transpert!ng water at h!gh rates K!dney ep!the!al cell - exac!re cells reas!ng - ↳ has the pee hydrophob!c !s to var as ected !n on other pere s!de i  FORMS Of TRANSPORT Mass!ve a) s!mple d!ffus!en b) fac!l!ated d!ffus!on ATPX trasport prote!ns h!gh - low Ör : gewose or aa blood+ cell I-channel prote!ns 2) carr!er prote!ns · enbedded !n cell memb. · changes shope · has a pore for cross!ng for them to more - sove of then det extend memb. through they bend and drag then to l!p!d b!leyer. Are low > - h!gh aga!nst cocentrat!on grad!ent TRANSPORTER PUMPS TYPES ↓ ↓ - · uses the · ATP protoeregy stored hydrel!s!s & energy & uph!ll uph!ll · uph!ll - bacter!a & downh!ll - archae at the same - m!tochadr!a - chloplest -OCs by ves!cles that fuse w plasma memb. or : secet!on , nerve comun!cat!on d!nz!ng cell eat!ng DOTTOS b) recepter-med!ated c) Phagocytos!s endocytos!s · most comment · engult!ng large · surface reseptered part!cles d!ssolved mot as ves!cles !ntegral prot.. 3 nucleus conta!ns geneme · : DNA pr!nc!pal s!te of synthes!s · cytoplasm : cas!sts cytool and orgaeles cytosal const!tutes [ ma!n c!te of · : To warse [ prote!n synthes!s and degradat!on more of cell than half of volume  ER- has r!bosences rough many > - produces l!p!d > - store for ca2+ smooth ER > - lack of r!bosones - d!spatche mod!fy!ten ER- prote!n Golg! apparatus then route en L!p!d Lysosome > - d!gest!ve enzyues - degrad!ng def!ct orgaels & le en before - should f!rst pass Lysosoves through endosomes perox!sove > - 02 react!ons enzyme evolut!onary or!g!ns 1) nucleus and cytosal : comun!cat!on through nuclear pore complex 2) ER , golg! , endoseve , lyzasenes and perax!sene : secetory and endocyt!c pathway funct!on!ng 3) m!tochad!a 4) plast!ds  r!bosonet r!bosones of prote!n + or synthes!s !n cytosal m!t. and plast!ds outs!de - fate depende osequence a cytol can certa!n sort!ng s!gnals orgaelle > - gated transport surface prote!n & RNA moves cytoso @nucleus !nce envelope nuclear pore complexes = select!ve gates translocat!on prote!n acos ger transmenbrone prote!n membrane - translocator a prote!n - d!ste usually must unfold res!cular transport I not cross!ng a membrane membrane exclosed - trasport the two must be !ntermed!ates topolog!cally pr!va (transport ves!clers) equ!valent -  donor - target - somble compact are res!des trasport trasferred l!er to l!ve - meubrene !s traneferred ↓ or!entat!on !s preserved - can't & most orgaelles be E R. constructed novo. -. = collagen synthes!s they requ!re !nfo !n orgaele · !ts membrane !s more than !tself. total vembrane half of the - !nd!v!s!on cells has to dupl!cate net!ce labyr!nth. the!r Ben orgaells & chronosomes - (tubules & sacs) L no new ER & m!tocad!a !nterconnect = they the!r membrae !s transmenbrare = = L!p!d & prot synthes!s cat!n!ous w!th outer = !ntracellular Ca2+ store => cat!l!ous sheet w!th !nternal s!ngle space · external seret!on prote!ns's = ER umar/!sternal almost all del!vered to Space - Erke · m!toclad!ad & perx!seal membrane l!ds product!on hepatocyte (l!ve celltype) ↳ has smooth ER. - pr!nc!pal s!te of product!on for l!poprote!n & azymes that catalyze = detox!fy l!p!d-soluble drugs Ca2t Storage muscle cells have a mod!f!ed smooth ER = sorcoplasm!c ref!culum tr!gges mysf!bre contract!on and relaxat!on - otel brone p. - becomes embedded , party tra!lededa 2) water soluble p. > - released to Etmen , fully traslocated um d!rected by ER to ER s!gnal sequace" part!cle (SRP) J s!gnal recogn!t!es membrane s!gnal meubrarecepte - o  memb. bound r!bosoves : synthes!s of the ER Isame only d!f ,.. prot traslocat!on prote!ns free r!bosoves : allthe prete!ns & The ER signal sequence on a newly formed polypeptide chain binds to SRP, which directs the translating ribosome to the ER membrane. ER ~h ↑N!cked d!go cee prote!nl > - about half & Sets rod!f!ed = b!osynthet!c funct!on et EL = glycoprote!n !n + prote!ns * only property folded end cytosch end nucleuy assembled prote!n can leave the ER but w!th se!n or trea!s > - !f m!sfolded or !ncompleted B!P = add chapeee prote!ns = or calnex!n > - !f fa!led = back to cytosel = degraded by proteasoves um central qual!ty boceme 3 s URNA's assoc!ate w!th subm!ts that r!bosoud prote!ns assembled !n have been transported to nuclay !n nucledus after the!r synthes!s cytoplasm L the they get exported to cytoplasm = they jo!n together !n nucledus : URNA process!ng the!r assembly to subm!ts · free r!boseues traslate mRNA for prote!ns that stay !n cytosel. attached ext. E2 · r!boseves on generates neubrone prote!ns that w!ll go outs!de of cell prote!ns or G Golg! Body · process of synthes!zed prote!ns w!th!ncell send!ng then outs!de · Corbenhydrate synthes!s · sort!ng and d!spatch!ng products for En · mak!ng of polysacche!des and GAG's. - l!es on the ex!t of ER attaches to L!p!ds = carbahydrates prot. & of ER s!de cha!ns. ol!gosadhe!de there groups serve as tags to d!rect prote!ns !nto ves!cles ↳ then traspet then to lysosoves. ysosones ↳ - cellular waste renoval / f!lled w!th soluble hydrol!t!c eneymes (hots · has un!que surround!ng membrane · ↳ h!ghly guycosylated for protect!on traysport prot !n hysoseve memb carry the d!gests -.. to cytosal endocytos!s-phagocytos!s-autophagy macrop!nocyto!s spec!al!zes : !n uptake of flu!ds membrare Mart!cles attached to plasma. neub 4 M!tochendr!a. (double-membran enclosed traspect 02 ATP -electron phesphoylat!on on - - m!tochad!al prote!n · f!rst synthes!zed as precuse !ncytosal · then translocated !nto n!t. by post-traglasyad mechan!sm. d!rect s!gnal sequences the · to appropr!ate sub precuses compat!ent mult!subun!t prote!n completes funct!on as traslocator - & Tom complex > - prote!n aross outer membrone · T!m complexes (22023) - "across !nne memb.  Prote!n Import ma!ntoned unfolded precrsor prote!ns are or part!ally folded by chaperas = Asc70 -M!tochad!al DNA !s locel!zed to matr!x - Il "!nhe!teed through maternel cha!ce- usable ergy engy 22 ox!dat!ve = phosphoylat!on used by m!tocled!al =H > - !nner !n matr!x > - c!tr!c ac!d or neubrote Kebs enzymes Alp E Centr!des trosome & - n!mal sel - cell d!v!s!on and cellular organ!zat!on - Statese centroseve = 2 pepend!cular centr!des to each daughte cell gets trasfered ~ starts d!v!d!ng before S-phase newly forced centr. Organ!zes m!tot!c sp!ndles. ema!nt!ng chanseve number · chages !n shape of cell neubrare by phagocytos!s a movement of cytoskeletal structures erox!sore & = detox!f!cat!on after !nflamat!on verbrace noDNAX r!bosores X s!ngle - - ↓ - the!r prote!ns are eneded !n nucleus (they get them by select!ve !mport from all cells have !t. eukaryot!c cytosel) - · ox!dat!ve enzymes = catalase , urate of!dare · s!te of oz ut!l!zat!on · cata!n eneyues that use 02 to renore Hz nur & catalar > - uses #202 to perox!dat!on react!ve - l!ve , k!dney cells Breakdown of Ac!d Mol B- ox!dat!on & Fatty = ( !nM!tocaa. fathy ac!d > - Asetyl CoA ↑ catalyze the f!rst reac. !n plasmalogen format!on - def!c!ency = myel!zat!on abnormal!ty => perox!sonal d!sorder d!sease. neurolog!cal ⑮ = d!mportance of prote!n !mport !n ellweger Syndave perox!sore = eupty bra!n perx!sos abn. , l!ver , k!dney  5 u ecloves the DNA def!nes nuclear cap.. -ve !nner nuclear membrane ; has prote!ns that acts as b!nd!ng s!tes fer nuclear Len!na & chonosones nuclear Com!na; acts s!te for as ancho!ng chronosomes & cytoskeleto 38 PC's nuclear evelope !s perforated by -g 30 prote!ns = nucleopo!ns ↳ scaffold -. n - chanel n. resmen - membrae r!ng 60 000 loges. I nuclear traff!c small < 5000 daltay prote!ns b!d!rect!onal treff!c constantly between cytosel I nucleus RNA's clear Local!zat!on s!gnals (NLSS) · sent!ng s!tes 7b!nd!e =. S select!v!ty of. !mport r!ch !n hys!ne & ag!n!ne. ImPORTIN recen!zed by nuclear !mport recepters must be = - EXPORTIN"export" = & export of large ma. W!th NPC's nuclear export s!gnal  GTPase RAN-energy for for nuclear !mport& export · G!Pase act!vat!ng prote!n (GAP) tr!gges GTP h!dolys!s converts Ran GTP- Ron GDP · ·Raexchange factr) !n cytosal > - Ran EDP !n nucles > - Ran GTP ORT Ron GTP leaves the carge Lago and GAP the ex!ts w!th GTP mattached. and ex!ts w!th then The Nuclear Lam!na ↳Mesa located on nuclear s!de of !nner membrane. cons!sts nuclear law!ng - g!ves shape and stab!l!ty to evelope !nteracts d!rectly w!th komat!n Com!na DNA develope + !nner membrae prot l!nk structure between =  Chronoseve structure ant!paralel DNA cha!ns It bods between base's , holds cha!ns together sugas and POG w!th cleot!ds l!nked together are forms a backbor chem!cal = g!ves DNA polo!ty s'hydogl 5' presphate J d!st!ngu!shable form & each strand has ab!l!ty to serve as template for synthe!s. the DNA and f!ghtly bound prote!n = chronat!n gene funct!onal : m!t of heed!tory DNA Chuman gere 3 2x10 genome : complete store of !nfo !n. exon : cod!ng sequences !ntres : !nterven!ng (ne cod!ng) sequences Chronosove 22-1 1.. 5 of huma geove  assoc!ated w!th DNA each gele !s regulatory sequences they are respons!ble for ge turn-on-off , express... levels · DNA molecule must repl!cated cop!es must car gues get seperated - - - repl!cate -port!oned !nto daughter cell -!nd!v!s!on controlled by ; · telomeres lends of chronosove) d repl!cat!on also protect or!g!n - the end of Chr. · centravere (K!nefochore) from be!ng broke 6 h!stor : prote!ns that b!nd DNA to form non-h!stene chosamel prof! called chemat!n = complex !s h!stens are respons!ble for > - f!rst bas!c level of pack!ng = nucleosome Th!store prote!ns then & f!rst found by !solat!ng w!th nucleases 147 pa!s boy DNA DNA nucleases breat dem L!nke DNA) (the the h!store octomer fors a prote!n after l!ner DNA gets degraded around wound. core -  nucles!ones Mu > - Th!store prote!ns then f!rst found by !solat!ng & w!th nucleases 147 pa!s boy DNA nucleases breat dem DNA L!nke DNA) (the after l!ner DNA gets degraded · the h!store octomer fors a prote!n [ 7 core around wound. all 4 h!stores shere mot!f > - h!ston fold 32-hel!tes folds f!rst b!nd ↓ FA-Haß ⑮He d tetreuer of X2 = Octane + X2 = tetrame -y ⑰Hab cor heterocloat!n : h!ghly condused form no prote!n cod!ng · eucherat!n : Less cadused  G TOSKELETON dynam!cstabl , adapte to cell g!ves shape rearage comparents of cell !nd!v!s!on , grow!ng , adoptat!on- - ↳ act!n , !ntermed!ate , m!crotubules (f!laments) they !nteract w!th prote!ns accessary as : motor prote!n regulates shape ATP - mechan!cal > legth stab!l!ty of f!lements face ey. Act!v F!laments prov!des streght & shope to b!lage cell surface project!ons Lamell!ped!a, f!lpod!a , streos!l!a , · > - m!crov!ll!. Z d!sc : attachment for act!ve Myos!n & Act!n ml!ne : myos!n T f!et moter prote!n that !dent!f!ed - skeletal muscle myos!c musl -generates force for centract!on. cans!sted myof!br!l : of sorceners ~ (str!py appereance) Contract & act!n sl!de each other myos!n w!thout short!ng rotubl ay - m!tot!c sp!ndle f!ber dur!ng cell d!v!s!on. · can form c!l!a (mot!le wh!ps , or sensor) & MTOC (m!crotubule orga!z!ng cater) : nucleat!on ↳ place l!ke catosore & catr!al · prote!ns uses to trasport cargo - K!nes!n 6 - dyne!n nuclear -!ntemed!ate Franats : L!ves the !nnerface ee = forms a protect!ve cage for DNA to an!mal cells t stab!l!ty : !n cytosel they form cables the => Kerat!n : anchersf!le hold ep!thel!al sheets : help nere cells cell-cell contact desmoson M!ll - · form tough appendage cell-matr!x" -her!desser !stemed!ateeen compact act!n globular - m!crotubules subun!ts 7Funct!ons. depends on cytosbeten cytosbeleton-cells I by act!n adhees funct!on > - cell to 1) alac!n - anche for act!n 2) desmosenes - anche for !ntermed!ate mall !ntest!ne & cytoskeletor- basal Con!na act!n-l!nked cell-mat!x 1) - anche act!n-matr!x 2) Lev!des mosemes - anche !ntermed!ate - matr!x L!ght junct!ons : cell-cell near apex prevents leakage across ep!thel!o basal gap junct!ons near : creates passage to cell-cell  cadhe!n : ely ar!mal cells [ cadhe!s Caft C · dependent - to · l!nked to cytos!deter C w!n !ntegn!s apterprot sen !ntegr!s eclasce las!cacathe!n e = B-cater!n & · ep!thec!al · bra!s 1-cate!s N-cadher!n desmocoll!n/desmogle!n · nerve , muscle , le · desmosen P- cadher!n · placenta and ep!dem!s Small !ntest!ne - # desmosenes are s!m!ler to adhere funct!ons but certa!n spec!al!zed cadher!n that l!ne - > !nterved!ate = f!erents = O ~ mechan!cal & O prov!des & = L L obv!ous. strength most zonula adhery eature I betred to des. - l!nked t > - act!n Kerat!n !n ep!tel cell f!laments · - · desm!n - !n heat musche  t!ght junct!on ; act as d!ff!sue bar!ers = fences ↓ blocks the backflew of glucse from basal s!de prote!ns ; claud!n Pessent!al · : format!on and funct!on · occlud!n : !mportant for l!m!t!ng permeab!l!ty (geç!rgenl!n) tr!cellul!n seal!ng cell. memb · : prevent!ng leakage gap junct!ons, creates d!rect charels cytoplasm-cytoplasm cells br!dge gops between are spaned by > - connet!n & !nnex!n gaps ↓ Xb = connexes mere cell-cell adres!n prote!ns; 1) !ntegr!ns > - cell-matr!x adhes!on · cat dependence 2) select!ng > - cell surface carbahydrate b!nd!ng - -traff!c of un!te blood celly 3) Ig superfar!ty - L , P , select!n -ICAM's - VCAM's - NCAm's ECM var!at!ve !n cell type * basal Lev!na !s a form of ECM connect!ve t!ssues - bone, tunde · certa!ns -formed from ECM produced by cells - lan!n!n ↓ - bears mechan!cal stress - type 4 colleg - n!doge - d!rect attachments are rore. - perlecon - f!bronect!n cell-matr!x func. ep!thel!al t!ssues - f!ghtly bond cells - basal lav!na cell-cell purc w!th!n ep!tel!um 2. cell-matex" w!th basal lov!na - mechan!cal stress !s transm!ted ECM maconolecules : 1) GAG's : repeat!ng d!saccle!de un!te = polysaccer!de cha!rs 2) f!brous prote!ns (collagen) 3) non-collages gl!coprote!ns  aggrece lerge : proteoglyce Sona deco!n : small / 2) chandro!t!n sulfate/dermaton sulfate 3) hepara sulfate syndeca : plasma membrace 4) keraton sulfate proteolycas. 8 Cellular Commun!cat!on memb > - memb ne!ghbour cells electr!cally - the response all s!gnal number chage of · can · s!gnal molecule may have d!fferent effects on tagets  cell surface resepters 1) lon-channel-coupled receptes !n synopt!c neurdy - , - · when the s!gnal mel b!nds, prote!ns opened - receptor are = neurotrasm!tter entrace 2) G-prote!n-coupled reseptors · regulates another !nact!ve target & pr!mary messengers comes prote!n from outs!de of cell ⑳ the act!ve target the -chem!cal secondary recepto b!nd!ng prote!n messeges prote!n cycl!ct hydroph!l!c 3) Enzyne-caped deepto d!ac!lglysel) hydrophob!c ca funct!on as enzyme !tself - an · the act!vated or enzyme they - > - prote!n secondary messages trasneubree prote!n · one way · acts as melecular key outs!de of > - L!gand b!nd!ng reg!on cell !nact!ve · form act!ve w!th s!gnal !ns!de enzyme b!nd!ng reg!on · of - > all  S!gnal!ng fathways of !ntracellular s!gnal prote!n 1) by Phosphorylat!on · prote!n h!nase adds POn % · prote!n phosphotose roves po Ser!non!ne) K!nases 2) by GTP b!nd!ng tyros!ne · sw!tch l!ke > - act!vated or !nact!vated by GTP b!nd!ng a) Large G- prote!n b) small GTPase !ntracellular s!gnal!ng complexes 1) preformed on scaffold prote!n & - prot!ns core together generates s!gnal!ng complex before s!gnal & the scaffeld holds the prote!ns close to each. 2) on act!vated recepto · receptos tu!l gets Pon - temporary when s!gnal cores - when s!gnal d!sappears > - complex get d!sassoc!ated 3) on phospho!nos!t!de dock!ng s!tes -the act!vat!on leads to format!on of PPSTD spense !s chay !n prote!n , response on be. fast · !f there !s chage !n gere express!on & new prote!n !s synthes!zed cl!ke trascr!pt!on) respace w!ll be slower cell s!gnal!ng v!a * G-prote!n-coupled receptos · largest surface resepter fam!ly 1 · polypept!de cha!n 7 t!mes passes the membrae · · sphe!cal, l!gand b!nd!ng reg!on !n center G L, B Y subm!ts prote!n > - , - when E pret !s !nact!ve ; & subm!t !s bound to GPP -when "!s act!ve ; 2 subm!t releases GDP and GTPL b!nds -G prof. becomes free , 2 , B , y goes to d!ff. targets st!mulate - !n MP , sone s!gnals receptos may change gere express!on - ,. G CAMP from ATP. prote!n fors - t!cox!de - !n sere s!gnals crother seconday mese gas - , !n muscle cells  cell s!gn!ng v!a & enzyme-coupled-receptes · tynos!ne K!nases (RTK's) - receptors d!me!zed by l!gand b!nd!ng close act!vate each o the -2 k!nase doma!ns core , w!th phosphaylat!on RTK's w!th ; Ras and Rho fac!l!es, funct!on w!th GTPases Pl-3 K!nase fam!ly (surv!val & greath) P1 K!naxe-Akt s!gnal act!vates mTOR : Clarge memal!a prot. K!nase) u cell growth Alternat!ve S!gnall!ng Pathueys v!a Gene Regulat!on 1) Notch S!gnall!ng Pathway - an!mal growth notch : a trasmembrac prote!n w!th one passage * !t the most d!rect s!gnal to cell prov!des > - nucleus act!vated when Delta b!nds. 2) Wht/B-cat!n Pathway 3) Hedgehog Pathway - also acts as Wat prof. · recepters are !nact!ve dur!ng absence of Hedgehog "must be close to act!vate th!s pathway · ↳ Hedgelog should b!rd ther. 4) FkB- dependent Pathway - stress , !nfledtoy , !nnate !mmune response. 5) ublear receptors are regulators of l!gand regulated trascr!pt!on -stro!d homans - ref!no!ds - thyo!d homoes -v!ta!n D · b!nds to DNA 9. THE CELL CYCLE cell has to materal to next past genet!c ge. - funct!on > - dupl!cate the about of DNA !n chasors cells segregate the cop!es !nt 2 !dent!cal daughter Sphase - > - Chronosove dupl!cat!on 10-12 h. DNA synthes!s chasenes M phase > - m!tere > - nuclear d!v!s!es sp!ndles < 1h. > - cytok!nes!s · DNA !n dupl!cated chonsens are !nterta!ned. s!ster he!n chr they held t!ghtly together by prote!n l!nkages.. together · !n Prophase > - two DNA mel. get cadeed !nto !ste chronat!ds. Y l!nked rema!n by ; > - nuclear evelope L = s!ster chanat!d colos!on > - s!ster chamat!ds become attached to m!tot!c sp!ndle · !n Metaphase > - al!gn!ng !n sp!ndle equate · !n Anaphane > - destruct!on of s!ster chromat!d crhes!e In s!ste chanet!ds pulled to oppos!te poles !n · !n Telophase > - sp!ndle !s d!sassembled , segregated Chr. package nucle! entrel Syste te rece!ved back frol preced !t centes ocentral components > - cycl!n-dependent K!nases ((dks) ↳ types of cycl!ne !n cell cycle; 1) Gf/S-cycl!ne : act!vate (dks !n GL !n!t!at!on of all cycle 2) S cycl!es - : b!nd to adbs after start st!mulat!on of chronosove dupl!cat!on !n Sphase 3) M-cycl!ns : act!vate (dks for entry to m!tos!s at G2/M po!nt 4) G-cycl!ng : govern act!v!tes of G/Scycl!ns. k prote!n act!vat!os!nact!ve CDK. prote!n loop !n act!ve s!te CDK - cycl!n b!nd!ng - more of the loop. Epat!al act!vat!on of -Ad act!vat!ng k!nace (CAK) => act!vat!on caplex - prote!n !nh!b!t!on by Wee1 , phosphoylates a pa!r of an !n the reef of CDK = !nh!b!ts act!v!ty by Cdc25, dephosphaylates"" = !ncrease !n act!v!ty l!n-cdK complex !nh!b!t!on CKIs (CDK !nh!b!ter prot.) !nact!vates b!nd!ng of complex. · - tras!t!on cyclock metaphase > - anaphase = anaphace premet!ng compet = destruct!on ef proteolyt!c regulatory prote!n -APC/C & destruct!on catalyzes ub!qu!tylat!on of L prote!ns S 1 "destroy!ng S- and M-cycl!ns secur!n (protects - the l!nkage that holds uses Fcoup!n l!gan control system also s!ster Chr. together (KI !n late G & ub!qu!tylates prote!ns central a helps the act!vat!on of S-Cdks & DNA rep. 61/S cycl!ne edestruct!on of !n early S APCIC act!v!ty > Subm!ts - CAC20 (dhl dependent , ↳ act!v!ty chages dur!ng cycle SCF subm!ts F-box act!v!ty > - prote!n dependent ↳ act!v!ty castal a to essure chomosove dupl!cat!on occurs once per cycle ↳ 1st step : late m!tos!s , early GL - !nact!ve DNA hel!cases to repl!cat!on or!g!n = prerepl!cat!ve complex (preRC) ↳ 2nd Step : Sphese - DNA hel!cases act!vates DNA unw!nds - DNA synthes!s = => 2hel!cases X unt!l new preRC !s assembled - hronosomal changes 1. Chronosove 3 dependent condensat!on to. s!ster-chromat!d 2 resolut!on = condens!n seve dupl!cat!n cell enters S phase Petro t!me sp ndles become = as attached centr!oe G/S-Cak help the !n!t!at!v ↓ centrosome chronosove segregat!on sp!ndle pulls : the s!des to secur!n destruct!on oppos!te polos after i  !nact!vat!on of (dkS - late M phase · tr!ggers late m!ta!s events - APC/C dependent · pronotes cytob!nes!s !n DNA prerepl!cat!ve coplex · no rep or!g!n. resett!ng catral · System ↳ cak !nact!v!ty = G gop phase