Ukulawulwa umsebenzi enzyme izindlela zabo

Njengoba iyunithi ndaba ophilayo, okuyinto isebenza njengoba iqoqo evulekile eziphilayo, iseli njalo yokuxhumana yangaphandle imvelo izidakamizwa kanye namandla. Ukuze silondoloze homeostasis kuwo kukhona iqembu izinto ezikhethekile wamaprotheni nemvelo - enzyme. Ukwakheka kwazo, imisebenzi nekulawulwa umsebenzi we enzyme wafunda biochemistry ekhethekile legatsha, enzymology ngokuthi. Kulesi sihloko, usebenzisa izibonelo ezishaya emhloleni zendlela azisebenzisa, sizocabangela izindlela ezehlukene zokwenza lokhu nezindlela zokuqondisisa umsebenzi enzyme esivela ezincelisayo ephakeme futhi abantu.

Izimo ezidingekile elilungile enzyme umsebenzi

ejenti eziphila abakhuthele ukuthi ngokukhetha zithonye ukusabela nokwenziwa kanye cleavage abonise impahla yayo okhanda amanye amathuba kumaseli ngaphansi kwezimo ezithile. Ngokwesibonelo, kubalulekile ukuthola kulokho ingxenye yeseli isifika inqubo yamakhemikhali, okubandakanya ama-enzyme. compartmentation Ngenxa (division of the cytoplasm kumasayithi) ukusabela abasiphikisayo zenzeka kwezingxenye zalo ezihlukahlukene futhi organelles.

Ngakho, amaprotheni zamagama Kwenziwa ku ribosomes futhi cleavage zabo - e hyaloplasm. Cellular umsebenzi ukulawulwa enzyme okuyinto catalyze ukusabela kwamakhemikhali okuphambene, akagcini ngokunikeza elilungile ukugeleza izinga lokugayeka kokudla, kodwa futhi kuvimbela ukwakheka amandla engenamsebenzi metabolic pathways.

multienzyme eziyinkimbinkimbi

inhlangano wezakhiwo futhi nemisebenzi yokusetshenziswa enzyme enzymatic amafomu iyunithi amaseli. Iningi zamakhemikhali ezenzeka kuwo zihlobene kakhulu. Uma endaweni multistage inqubo yamakhemikhali umkhiqizo ukusabela kokuqala kuyinto reactant ukuze uthole okunye, kulesi simo, ilungiselelo kwezendawo enzyme iseli sivezwe ikakhulukazi kakhulu.

Kumele kukhunjulwe ukuthi enzyme kanti ngokwemvelo bangabantu elula noma amaprotheni eziyinkimbinkimbi. Futhi uzwela kwabo substrates yeselula ngenxa ngokuyinhloko ushintsho yokulungisa yayo kwezendawo isakhiwo ephakeme noma quaternary we peptide. Enzyme basabela izinguquko kuphela nemingcele yeselula ezifana amakhemikhali ukwakheka hyaloplasm, lokuhlushwa reactants kanye nemikhiqizo ukuphendula, izinga lokushisa, kodwa futhi yezinguquko amaseli engomakhelwane noma oketshezini extracellular.

Kungani iseli ihlukaniswe linezingxenye

Uyacabangela futhi okunengqondo kudivayisi izilwane zasendle siyamangalisa. Lokhu kusebenza ngokugcwele izenzo ukuphila nobuntu iseli. Ukuze usosayensi wemithi Kucacile ukuthi nxazonke enzymatic zamakhemikhali, isibonelo synthesis glycolysis kanye glucose Awukwazi ukuqhubeka tube efanayo. Pho-ke, kwenzeka okuphambene kule hyaloplasm ukuphendula kuseli eyodwa, okuyinto substrate ngenxa yokuziphatha kwabo? It kuvela ukuthi okuqukethwe yeselula - the cytosol, - lapho abasiphikisayo chemical izinqubo abazenzi spatially ahlukaniswe kanye namafomu angawodwa loci - linezingxenye. Ngenxa indlela esisabela ngayo umzimba ezincelisayo ephakeme futhi abantu ihanjiswa ikakhulukazi ngokunembile, futhi imikhiqizo umzimba siguqulelwa ifomu, lingena kalula ngokusebenzisa izindonga cell amasayithi. Ngokulandelayo, abubuyisela isakhiwo yayo yasekuqaleni. Ngaphezu cytosol, uketshezi eziqukethwe organelles: ribosomes, mitochondria, i-nucleus, lysosomes.

Indima enzyme amandla umzimba

Cabanga decarboxylation oxidative ka pyruvate. Regulation womsebenzi okhanda amanye amathuba enzyme ke ibilokhu wafunda kahle enzymology. Le nqubo kwamakhemikhali senzeka mitochondria - organelles dvumembrannyh lamaseli eukaryotic - futhi inqubo Lesisemkhatsini phakathi anoxic eqhekeza glucose ne umjikelezo Krebs. Pyruvate eziyinkimbinkimbi dehydrogenase - PDH - iqukethe ezintathu enzyme. Ngo ezincelisayo ephakeme futhi abantu ukunciphisa kwenzekani nge okwandisa lokuhlushwa acetyl-CoA futhi Nath, okusho ukuthi uma okunye ematfuba emfundvo molecule acetyl-CoA yayo. Uma iseli idinga izingxenye ngaphezulu amandla futhi kudinga acceptor molecule emisha ye okhulisa ukusabela tricarboxylic umjikelezo acid, ama-enzyme ziyasebenza.

Kuyini okusithiyayo allosteric

WokuLawula umsebenzi enzyme kungaba kwenziwe nge izinto ezikhethekile - okhanda amanye amathuba inhibitor. Zingase covalently exhumene loci enzyme ethile, ngokudlula indawo yayo asebenzayo. Lokhu kuholela ukusonteka kwezendawo isakhiwo kulethe futhi ngokuzenzekelayo kufaka nokuncipha impahla yayo enzymatic. Ngamanye amazwi, kukhona isiqondiso allosteric womsebenzi enzyme. Siphinde engeza ukuthi lolu hlobo isinyathelo okhanda amanye amathuba esingokwemvelo enzyme oligomeric, isb yalabo abanhliziyo molecule aqukethe ezimbili noma ngaphezulu polymeric amaprotheni subunits. PDH-eziyinkimbinkimbi okuxoxwe ngazo isihloko langaphambilini nje liqukethe ezintathu enzyme oligomeric: dehydrogenase pyruvate, a dehydrogenase futhi degidrolipoil gidrolipoil transatsetilazu.

enzyme zokulawula

Ucwaningo e Enzymology esungulwe yokuthi izinga zamakhemikhali kuncike kokubili okuhlushwa umsebenzi ekwandeni. Ngokuvamile, izindlela ezinkulu umzimba aqukethe enzyme elawula izinga yokusabela nhlobo amasayithi yayo.

Zibizwa ngokuthi ama-zokulawula kanye ngokuvamile kuthinte bebona eyinkimbinkimbi, futhi bayakwazi ukubamba iqhaza iningi kancane chemical izinqubo ukusabela engelapheki, noma ujoyine reactants ezindaweni legatsha e pathway umzimba.

Kukanjani nokuxhumana peptide

Enye indlela lapho isiqondiso womsebenzi enzyme kwenzeka kuseli kuyinto nokuxhumana amaprotheni-amaprotheni. Kuyini lokhu? amaprotheni Wokulawula is aye ahlanganiswa namanye ukuze engqamuzaneni enzyme, lapho ukusebenza kwabo. Ngokwesibonelo, ama-enzyme adenylate cyclase esisogwini ebusweni engaphakathi ulwelwesi cell baphinde baxhumane izakhiwo ezifana ama-hormone yokwamukela kanye peptide ngokufanele phakathi kwaso enzyme. Kusukela kwaphumela kwakwakhe i-hormone yokwamukela eshintsha yayo amaprotheni Lesisemkhatsini isiqinisekiso kwendawo, le ndlela ngcono izakhiwo okhanda amanye amathuba adenylate cyclase e-biochemistry ibizwa ngokuthi "ukwenza kusebenze ukubusa ngenxa amaprotheni zokulawula."

Protomers kanye nendima yabo biochemistry

Leli qembu izidakamizwa, ngaphandle kwalokho okuthiwa amaprotheni kinases, shesha ukudluliselwa anion PO ₄ ^3- gidroksogrupp acid acid lenye macromolecule peptide. WokuLawula umsebenzi enzyme protomers ezocatshangelwa yithi njengesibonelo wamaprotheni kinase A.-molecule - tetramer yakhiwa subunits ezimbili okhanda amanye amathuba kanye ezimbili zokulawula kanye peptide ayisebenzi njengoba ekwandeni nje esifundeni ezingokomthetho protomer enamathiselwe molecule amane ekamu. Lokhu kubangela tingucuko isakhiwo kwezendawo amaprotheni zokulawula, okuholela ukukhululwa kwe ezimbili okhanda amanye amathuba isebenze amaprotheni izinhlayiya, isb dissociation protomers. Uma behlukile subunits lelawula ekamu molecule amaprotheni kinase eziyinkimbinkimbi ngasebenzi futhi ubuyiselwa ekubeni tetramer, njengoba kwenzeka Association okhanda amanye amathuba kanye zokulawula peptide izinhlayiya. Ngakho, indlela ukulawulwa umsebenzi enzyme okuxoxwe ngazo ngenhla ukunikeza imvelo yabo emuva.

Chemical ukulawulwa umsebenzi enzyme

Biochemistry futhi ecwaninga lezi zinto izindlela yokulawulwa kwezimboni enzyme umsebenzi, phosphorylation, dephosphorylation. Mshini wesi womsebenzi enzyme Kulokhu has ifomu elilandelayo: acid acid izinsalela of enzyme equkethe OH ^-, ukushintsha kwamakhemikhali yabo ukuguqulwa ngenxa ukuchayeka fosfoproteinfosfataz. Kulokhu, ukulungiswa amenable ukuba isayithi asebenzayo we-enzyme, lapho ama-enzyme ngasizathu simbe ke yenza kubo futhi abanye - inhibitory. fosfoproteinfosfataz izakhiwo okhanda amanye amathuba ngokwabo kulawulwa hormone ngokulandelana. Ngokwesibonelo, isitashi isilwane - glycogen - namafutha phakathi ukudla abaphukile phansi pheshana emathunjini, noma ngaphezulu ngokunembile, in the duodenum bedle glucagon - enzyme pancreatic.

Le nqubo okuthuthukiswa phosphorylation enzyme trophic emathunjini. Esikhathini esiyiminyaka esebenzayo of kokudla esiswini lapho ukudla kungena esiswini phakathi duodenum, glucagon zamagama buyathuthuka. Insulin - omunye enzyme pancreatic ezivezwa alpha amaseli zalezi ziqhingi ka-Langerhans, - baxhumana yokwamukela, kuhlanganise phosphorylation mshini efanayo ama-enzyme.

proteolysis esinqunyiwe

Njengoba ubona, amazinga wesi womsebenzi enzyme iseli nhlobonhlobo. Ukuze enzyme ukuthi kukhona ngaphandle cytosol noma organelles (e oketshezini olungenambala olusegazini noma e pheshana emathunjini), indlela ukusebenza yinqubo hydrolysis ka peptide izibopho CO-NH. Kudingeka, kusukela enzyme enjalo kuhlelwe ifomu esingasebenzi. Mpilo is wajinge wanamatsela ngu enzyme peptide ingxenye futhi okusele kukhonjelwe ukuguqulwa isakhiwo isayithi asebenzayo. Lokhu kuholela yokuthi enzyme "kuhlanganisa luyasebenza", okungukuthi, uyakwazi ukuthonya inkambo iyinkimbinkimbi inqubo yamakhemikhali. Ngokwesibonelo, ngasebenzi enzyme pancreatic trypsinogen hhayi uhlaba amaprotheni ukudla ngokufaka duodenum. Kuthatha indawo ngaphansi isenzo proteolysis enteropeptidase. Ngemva kwalokho ama-enzyme inikwe amandla futhi manje esibizwa trypsin. proteolysis kwengxenye - inqubo esethola. Kwenzeka ezimweni ezifana ukusebenza enzyme ukuthi sokudiliza polypeptides e igazi ekunqandeni.

Indima lokuhlushwa izinto kusukela umzimba cell

WokuLawula umsebenzi ukutholakala enzyme substrate Okubukwe ngokwengxenye contact isihlokwana "eziyinkimbinkimbi multienzyme." Izinga ukusabela okhanda amanye amathuba ezazenzeka izigaba eziningana, sixhomeke kakhulu isibalo molecule indaba kokuqala ungaphakathi hyaloplasm amaseli noma organelles. Lokhu kungenxa yokuthi ijubane endleleni umzimba ngokuqondile wakhona lokuhlushwa starting impahla. I emikhulu reactant molecule ise cytosol, ayanda ijubane zonke okwalandela zamakhemikhali.

isiqondiso allosteric

Enzyme omisebenzi ilawulwa hhayi nje ngenxa yezinkulumo lokuhlushwa ukuqala izinto, reagents, kodwa futhi izinto effector, libhekene ngakho ngokuthi isiqondiso allosteric. Iningi la ma-enzyme ethulwa imikhiqizo Lesisemkhatsini umzimba kuseli. Ngenxa effectors futhi iqaliswe ukulawulwa umsebenzi enzyme. Biochemistry wabonisa ukuthi lezi zakhi, okuthiwa ama-enzyme allosteric kubaluleke kakhulu umzimba amaseli, njengoba beye benza ezwela eliphezulu ngokwedlulele yezinguquko homeostasis yayo. Uma enzyme kuvimbela yokusabela chemical, ie kunciphisa ijubane layo uma igijima - ubizwa ngokuthi effector ezimbi (inhibitor). Endabeni okuphambene, uma kukhona ukwanda izinga yokusabela, kuziwa Activator - a effector omuhle. Ezimweni eziningi izinto kokuqala, okusho ukuthi reactants engena ekusebenzisaneni chemical ukudlala activators indima. Yiqiniso, imikhiqizo ezakhiwe ukusabela multistage sokuziphatha njengomncane inhibitor. Lolu hlobo isiqondiso ukwakhiwa phezu ubuhlobo lokuhlushwa reactants kanye nemikhiqizo, ngokuthi heterotrophic.