Ummiselo yomsebenzi enqanda neendlela zabo

Njengoko iyunithi umcimbi ophilileyo, imisebenzi njengoko njengoluhlu lwezixokelelwano ezivulekileyo eziphilayo, iseli uhlala ukunxibelelana kunye zangaphandle bume kweziyobisi kunye namandla. Ukuze sihlale homeostasis kuso kukho iqela kwezinto elikhethekileyo protein indalo - enzymes. Isakhiwo, umsebenzi nokulawula umsebenzi we-enzayim wafundela ngamachiza isebe okhethekileyo, enzymology ebizwa. Kweli nqaku, besebenzisa izixhobo eziphathekayo, siza kuqwalasela iindlela ezahlukeneyo kunye neendlela zokulawula umsebenzi enqanda ezendeleyo ezanyisayo ephakamileyo kunye nabantu.

Iimeko eziyimfuneko ukuze umsebenzi ngokupheleleyo enzyme

arhente eziphilayo asebenzayo emane kuchaphazela zombini indlela nokwenziwa kunye cleavage babonise iimpawu zayo ekujonganeni iiseli phantsi kweemeko ezithile. Umzekelo, kubalulekile ukufumana oko yinxalenye iseli ukwenzeka inkqubo imichiza, ebandakanya enzymes. compartmentation Ngenxa (kwisahlulo kukho icytoplasm ukuya kwiziza) abasabela zingavisisani kwenzeka kwiindawo ezahlukahlukeneyo kunye organelles.

Ngenxa yoko, Iprothini kuyondelelaniswe lwenziwa kwi ribosomes kunye cleavage zawo - hyaloplasm. ulawulo umsebenzi yeselula enqanda leyo catalyze reactions kwemichiza esahlukileyo, ayiboneleli kuphela ngokupheleleyo izinga ukuhamba ukutya, kodwa kuthintela ukuyilwa amandla iindlela engenamsebenzi pathways.

multienzyme complex

umbutho lokwakheka kwaye kukwasetyenziswa yona enzyme, iifomu enzymatic iyunithi iiseli. Uninzi abasabela yemichiza ezenzeka kulo zihlobene. Ukuba kukho imichiza imveliso multistage basabela njani lokuqala reactant ngenxa ngakumbi, kulo mzekelo, eli lungiselelo lwendawo enqanda esiseleni kubonakaliswa ngokukodwa ngamandla.

Kufuneka kukhunjulwe ukuba enzyme obulula uhlobo okanye weeproteni ezintsonkothileyo. Novakalelo kwabo substrates zeselula ngenxa ngokuyintloko kutshintsho kuqwalaselo lwayo lomhlaba lwesakhiwo ephakamileyo okanye koqeqesho le peptide. Enzyme basabela akaguquki kuphela cellular iparameters ezifana imichiza ukwakheka hyaloplasm, lwee- reactants kunye nemveliso reaction, ubushushu, kodwa utshintsho kwi iiseli ezikufutshane okanye kulwelo extracellular.

Kutheni iseli zihlukaniswe kwiindawo

Unengqondo yaye enengqondo isixhobo zasendle nje emangalisayo. Oku kusebenza ngokupheleleyo wabonakala ubomi uphawu kwiseli. Kuba inzululwazi wemithi kwacaca ukuba zodidi reactions enzymatic yamachiza, umzekelo Yindibanisela glycolysis kunye glucose ayikwazi ukuqhubeka kwi ityhubhu efanayo. Njani, ke, lo malunga kwenzeka indlela hyaloplasm enye iseli, nto leyo ke zeendawana ngenxa yehambo yabo? Kubonakala ukuba imixholo cellular - le cytosol, - amagumbi - apho iinkqubo yemichiza bamchasa uYesu ukuba endawo ezahlulwe kunye neefom ekwanti ngeso wenziwe. Ngenxa ukusabela zabo pathways ezincancisayo ephakamileyo abantu kulawulwa ngakumbi ngqo, kunye neemveliso pathways senziwa similise ifomu, ngokulula ingena iindonga sites cell. Okulandelayo, zibuyisela isakhiwo yayo yoqobo. Ukongeza cytosol, i-enzayim eziqulathwe organelles: ribosomes, mitochondria, inucleus, lysosomes.

Indima enzyme ukutya amandla

Cinga oxidative decarboxylation of pyruvate. Ulawulo nomsebenzi ekujonganeni enqanda kuye kufundwe kakuhle enzymology. Le nkqubo ezinto ithatha indawo kwi mitochondria - organelles dvumembrannyh zeeseli eukaryotic - yaye kukho inkqubo eliphakathi phakathi glucose oqhekeza anoxic kunye nomjikelo Krebs. Pyruvate complex dehydrogenase - PDH - iqulethe enzyme ezintathu. Xa ezanyisayo aphezulu kunye nabantu kwehlisa eyenzekayo ukwandisa abasuka acetyl-awula kunye eTahanati, okt kwimeko ezizezinye amathuba emfundo molecule acetyl-awula. Ukuba iseli ufuna iinxalenye ngaphezulu amandla kwaye ifuna molekyuli ezintsha acceptor basabele okhulisa tricarboxylic umjikelo acid, i-enzayim luyasebenza.

Yintoni na inhibition allosteric

Regulation yomsebenzi enqanda nga kwenziwa izinto ezikhethekileyo - encedisa ukuqalisa inhibitors. Mhlawumbi covalently inxulumene ngqo enzyme ngeso, ngokudlulisela kwisiza esebenzayo. Oku kukhokelela deformation lomhlaba lobume kuvala kwaye ngokuzenzekelayo kuquka ukwehla iipropati yayo enzymatic. Ngamanye amazwi, kukho ulawulo allosteric lomsebenzi enzyme. Kwakhona echaza ukuba le uhlobo logwayimbo zokuphosa enzayim ezingundoqo oligomeric, ngamanye amazwi abo molekyuli luqulathe subunits ezimbini okanye ngaphezulu protein polymeric. PDH-complex kuxoxwa ngazo kwisihloko oludlulileyo nje iqulethe enzyme ezintathu oligomeric: dehydrogenase pyruvate, a dehydrogenase kunye degidrolipoil gidrolipoil transatsetilazu.

enzyme zokulawula

Uphando e Enzymology elisekwe yokuba izinga ekudibaneni kwemichiza kuxhomekeke zozibini yoxinaniso kunye nomsebenzi lo kuvala. Amaninzi, endleleni ezinkulu pathways ziqulathe enzayim elawula isantya reaction kumaziko alo onke.

Zibizwa ezilawulayo kwaye ngokuqhelekileyo kuchaphazela indlela lokuqala zakhiwo, kwaye inxaxheba ezininzi kwiinkqubo wemichiza okucothayo ukusabela vuhlayiseki, okanye ujoyine reactants kwiindawo yesebe indlela metabolic.

Njani na ukusebenzisana peptide

Enye indlela apho ummiselo yomsebenzi enzyme lwenzeka kwi iseli intsebenziswano ziiprotein-protini. Yintoni na? iiproteni Regulatory kuyamanyaniswa ku kwemolekyuli enzyme, apho ukusebenza kwazo. Umzekelo, i-enzayim adenylate cyclase ibekwe phezu engaphakathi yeseli inwebu kwaye basebenzisane kunye nezakhiwo ezifana hormone receptor kunye peptide ilahlwe phakathi kwayo kunye ne-enzyme. Ekubeni kubangela compound hormone receptor utshintsha iproteni eliphakathi yokuqinisekisa yayo lomhlaba, le ndlela yokuphucula iimpawu zokuphosa of adenylate cyclase ngamachiza ubizwa ngokuba "iiproteni regulatory vuliwe awabekwa ngenxa."

Protomers kunye nendima yabo ngamachiza

Eli qela kwezinto, ebizwa protein kinases, ukukhawulezisa ukutshintshwa kwe anion PO ₄ ³ gidroksogrupp acid acid emniniyo macromolecule peptide. Regulation yomsebenzi enqanda protomers ziya kuqwalaselwa sithi umzekelo protein kinase A. It molecule njengoko - tetramer ubunjwe subunits ezimbini zokuphosa ezimbini ezilawulayo kunye peptide ayisebenzi njengoko ngumnxibelelanisi logama nje kummandla olawulo protomer zinemoletyhule inkampu ezine iqhotyoshelwe apha. Oku kubangela inguqu kubume lwendawo iiprothini zolawulo, nto leyo ekhokelela nokukhululwa amasuntswana zokuphosa ezimbini iyasebenza protein, ngamanye protomers dissociation. Ukuba eyahlukileyo evela subunits regulatory kweminquba molecule, iiproteins kinase complex engasebenziyo kwakhona ukuba tetramer, njengokuba kwenzeka Association encedisa ukuqalisa kunye amasuntswana peptide yolawulo. Ngenxa yoko, indlela ummiselo umsebenzi enzyme kuxoxwe ngasentla ukunika yimvelo yabo ingathityazwa.

ulawulo chemical umsebenzi enzyme

Eziphilayo sasifunda ezi ezisebenza ummiselo umsebenzi transcriptase, phosphorylation, dephosphorylation. Indlela wesi yomsebenzi enzyme kweli cala le fomu ilandelayo: iintsalela acid acid ye-enzyme equlathe KOWU ^-, ukutshintsha ukulungiswa yemizimba yethu ngenxa yokuba sesichengeni fosfoproteinfosfataz. Kulo mzekelo, ukulungiswa efanele kwindawo ebonakalayo enzyme, apho enzayim ngenxa yesizathu esithile ukuba isebenze kubo abanye - inhibitory. fosfoproteinfosfataz iipropati zokuphosa ngokwabo kulawulwa hormone ithuba. Umzekelo, starch isilwanyana - glycogen - kunye namanqatha phakathi akukhe idilikile kwisiqwenga zesisu, okanye ngaphezulu ncam, kuloo duodenum phantsi kwempembelelo glucagon - enzyme pancreatic.

Le nkqubo kunyuswa phosphorylation enqanda trophic zesisu. Kweli xesha asebenzayo ukwetyisa xa ukutya engena evela esiswini kulo duodenum, glucagon kuyondelelaniswe kunyuswa. Insulin - omnye transcriptase pancreatic eveliswe iiseli alpha le nemisele ka Langerhans, - esinxibelelana receptor, kuquka phosphorylation womatshini efanayo enzyme.

proteolysis akakhethi

Njengoko ubona, amanqanaba ulawulo lomsebenzi enzyme kwiseli lwaya. Kuba enzayim lungaphandle cytosol okanye organelles (kwi-plasma yegazi okanye phecana zesisu), indlela kusebenze inkqubo haydrolisis neentambo peptide CO-NH. Kufuneka, ekubeni loo enzyme kuhlelwe ngohlobo opholileyo. Molecule wanamathela yi enzyme peptide isabelo kwaye intsalela kuxhomekeke loyamano isakhiwo site esebenzayo. Oku kukhokelela ekubeni enzyme "uquka imeko ukusebenza", oko kukuthi, uyakwazi ukuphembelela indlela yalo imichiza. Umzekelo, i-enzayim pancreatic engasebenziyo trypsinogen na lusicande iiproteni ukutya nghena duodenum. Kuthatha indawo phantsi yesenzo proteolysis enteropeptidase. Emva koko i-enzayim luvuliwe yaye ngoku ebizwa trypsin. proteolysis Partial - le nkqubo ingathityazwa. Senzeka kwiimeko ezifana uqalile okanye ipoti ye-enzayim ndoyidiliza polypeptides e igazi ekunqandeni.

Indima abasuka izixhobo ukuqala kwiseli nethe

Regulation yomsebenzi ngokufumaneka enzyme zeendawana zibonwa eyase isihlokwana zoqhagamshelwano "isakhiwo multienzyme." Izinga abasabela zokuphosa ukuthatha kuqhubeka ngokwezigaba eziliqela, buxhomekeke kakhulu kwinani iimolekyuli umbandela oqala ngayo iiseli hyaloplasm okanye organelles. Oku kubangelwa yinto yokuba isantya indlela pathways kukuba kisekiyo ngqo kwindlela ekwakugquba ngayo umbandela yokuqala. Iimolekyuli reactant ezinkulu elime kule cytosol, kungona isantya zonke ekudibaneni kwemichiza ezilandelayo.

ummiselo allosteric

Enzyme abankonzo ilawulwa hayi kuphela uyondelelwano lwee- loqalo izinto, wezenzi, kodwa ke izinto effector, ebonakala ngu ummiselo ukuze kuthiwa allosteric. Inkoliso yezi enzymes zinikwa iimveliso intermediate emzimbeni kwiseli. Ngenxa effectors kwaye yaphunyezwa ummiselo msebenzi enzyme. Eziphilayo kwabonisa ukuba le khompawundi, ebizwa enzyme allosteric zibaluleke kakhulu nethe weseli, njengoko befumana uvakalelo oluphezulu kakhulu utshintsho homeostasis yayo. Ukuba enzyme abangaphangeliyo indlela imichiza, oko kukuthi lunciphisa ngesantya - ibizwa ngokuba effector negative (inhibitor). Kwimeko esahlukileyo, xa kukho ukwanda kwezinga reaction, kufikwa kwi isilumeki - a effector HIV. Kwiimeko ezininzi izinto ukuqala, ngamanye le reactants engena intsebenziswano imichiza zidlala activators indima. Kakade ke, loo mveliso lisekwa reactions multistage benza njengoko inhibitor. Olu hlobo ummiselo yakhiwe kwi ukuzalana lwee- reactants kunye neemveliso, ebizwa heterotrophic.