A tsari na aiki na enzymes da su hanyoyi

Kamar yadda wani sashi ne na rai al'amari, wanda ayyuka a matsayin sa na bude nazarin halittu tsarin, da cell ne kullum sadarwa tare da waje yanayi abu da kuma makamashi. Don kula homeostasis a cikinsa akwai wani rukuni na musamman da abubuwa na gina jiki da yanayi - enzymes. Structure, aiki da kuma tsari na aiki na enzymes karatu musamman reshe Biochemistry, enzymology kira. A cikin wannan labarin, ta amfani kankare misalai, za mu tattauna daban-daban sunadaran da kuma hanyoyin da gudãnar da ayyukan enzymes muhimmi a cikin mafi girma da dabbobi masu shayarwa da mutane.

A yanayi dole ga mafi kyau duka enzyme aiki

Ta ilimin aiki jamiái cewa selectively shafi duka da assimilation dauki da kuma tsakiyan nonon nuna ta catalytic Properties a cikin sel a karkashin wani yanayi. Alal misali, yana da muhimmanci a gano a cikin abin da ɓangare na cell daukan sanya wani tsarin sunadarai, wanda ya shafi enzymes. Saboda compartmentation (da rabo daga cikin cytoplasm ga shafukan) antagonistic halayen faruwa a sassa daban-daban da kuma wasu gabbansa.

Saboda haka, furotin kira ne da za'ayi a cikin ribosomes da su tsakiyan nonon - a hyaloplasm. Salula aiki tsari na enzymes wanda tsara biochemical halayen m, ba kawai na samar da mafi kyau duka kwarara kudi na metabolism, amma kuma ya hana samuwar makamashi m rayuwa tafarkin.

multienzyme hadaddun

Tsarin da kuma aikin kungiyar na enzymes, enzymatic siffofin naúrar Kwayoyin. Mafi yawa daga cikin sinadaran halayen da ya faru a shi ne m. Idan a wani multistage tsarin sunadarai samfurin na farko dauki wani reactant domin kara, a cikin wannan yanayin, da na sarari tsari na enzymes a cikin cell da aka bayyana, musamman karfi.

Yana dole ne a tuna da cewa enzymes ne da yanayi mai sauki, ko hadaddun sunadarai. Kuma su ji na ƙwarai to salula substrates saboda da farko zuwa canji a yadda na sarari sanyi na manyan ko quaternary tsarin da peptide. Enzymes da amsa ga canje-canje ba kawai a cikin salon salula sigogi kamar juyawar sunadarai abun da ke ciki hyaloplasm, maida hankali reactants kuma dauki kayayyakin, da yawan zafin jiki, amma kuma ya canje-canje a cikin makwabciyar Kwayoyin ko a cikin extracellular ruwa.

Me cell kasu kashi compartments

M da ma'ana namun dajin na'urar kawai ban mamaki. Wannan cikakken shafi rayuwar bayyananen halayyar da cell. Domin masanin kimiyya sunadarai sarari yake cewa multidirectional enzymatic sinadaran halayen, misali kira na glycolysis kuma glucose ba zai iya ci gaba a cikin wannan bututu. To, ta yaya kishiyar auku a dauki hyaloplasm guda cell, wanda shi ne substrate for su hali? Sai dai itace cewa da salon salula abinda ke ciki - da cytosol, - a cikinsa, da antagonistic sunadarai matakai suna da za'ayi spatially rabu da ya zama ruwan dare siffofin loci - compartments. Saboda su na rayuwa halayen na mafi girma dabbobi masu shayarwa da kuma mutane suna kayyade musamman daidai, da kuma na rayuwa kayayyakin canza kama zuwa nau'i, sauƙi ratsa ta cikin ganuwar cell shafukan. Next, sun mayar da asali tsarin. Bugu da kari ga cytosol, da enzymes kunshe ne a cikin wasu gabbansa: ribosomes, mitochondria, tsakiya, lysosomes.

Rawar da enzymes a samar da makamashi metabolism

Ka yi la'akari da oxidative decarboxylation na pyruvate. Regulation na catalytic ayyuka na enzymes an da karatu enzymology. Wannan biochemical aiwatar daukan wuri a cikin mitochondria - dvumembrannyh da wasu gabbansa da eukaryotic Kwayoyin - da kuma wani tsaka-tsaki aiwatar tsakanin anoxic tsagawa glucose da kuma cikin Krebs sake zagayowar. Pyruvate dehydrogenase hadaddun - PDH - ƙunshi uku enzyme. A mafi girma dabbobi masu shayarwa da mutane rage faruwa tare da kara maida hankali acetyl-CoA da NATH, watau a cikin hali na madadin a damar samun ilmi da kwayoyin na acetyl-CoA. Idan cell bukatar karin rabo na makamashi da kuma bukatar sabon Mai karɓar kwayoyin domin karawa halayen tricarboxylic acid sake zagayowar, da enzymes aka kunna.

Mene ne allosteric hanawa

Regulation da aiki na enzymes za a iya za'ayi da musamman abubuwa - catalytic hanawa. Sun iya covalently nasaba da takamaiman loci enzyme, jingine ta aiki site. Wannan take kaiwa zuwa wani sarari nakasawa na kara kuzari da kuma tsarin ta atomatik entails a rage a cikin enzymatic Properties. A wasu kalmomin, akwai allosteric tsari na enzyme aiki. Mun kuma ƙara da cewa wannan nau'i na catalytic mataki muhimmi oligomeric enzymes, Ina nufin wanda kwayoyin kunshi biyu ko fiye polymeric gina jiki subunits. PDH-hadaddun tattauna a baya suna ne kawai ya ƙunshi uku oligomeric enzyme: pyruvate dehydrogenase, a dehydrogenase da degidrolipoil gidrolipoil transatsetilazu.

dokokin enzymes

Bincike a cikin Enzymology kafa hujja da cewa da kudi na sinadaran halayen dogara duka biyu a kan maida hankali da kuma ayyuka na kara kuzari. Mafi sau da yawa, da manyan rayuwa tafarkin dauke da enzymes cewa gwada dauki kudi a duk ta shafukan.

Suna da ake kira yau da kullum da kuma yawanci shafi na farko dauki na hadaddun, kuma zai iya shiga cikin mafi m sunadarai matakai a rashin komowar dauki, ko shiga reactants a reshe da maki a rayuwa hanya.

Ta yaya ne peptide hulda

Daya hanyar da wanda da tsari na enzyme aiki auku a wani cell ne mai gina jiki-gina jiki hulda. Mene ne wannan? Kullum sunadaran da aka garwaya da enzyme kwayoyin, inda su kunnawa. Alal misali, adenylate cyclase enzyme located a kan ciki surface daga cikin cell membrane da kuma iya mu'amala da irin wannan Tsarin kamar yadda hormone tsoka mai amsa sigina da peptide zubar tsakanin shi da enzyme. Tun lokacin da sakamakon fili hormone tsoka mai amsa sigina ta sauya gina jiki matsakaici sarari tabbatarwa, wannan hanya na inganta catalytic Properties na adenylate cyclase a Biochemistry ake kira "kunnawa saboda Accession kullum sunadaran."

Protomers da kuma rawar da suka taka a Biochemistry

Wannan rukuni na abubuwa, in ba haka ba ya kira gina jiki kinases, gaggauta canja wuri na anion PO ₄ ^3- gidroksogrupp amino acid na zuwa peptide macromolecule. Regulation da aiki na enzymes protomers za a yi la'akari da mu a matsayin misali na gina jiki kinase A. Yana kwayoyin - tetramer aka hada biyu catalytic da biyu kullum subunits da peptide ba aiki a matsayin mai kara kuzari muddin dokokin yankin for protomer a haɗe da wani hudu sansanin kwayoyin. Wannan sa canji na sarari tsarin dokokin sunadarai, wadda take kaiwa zuwa saki na biyu catalytic kunna gina jiki gaɓũɓuwa, Ina nufin dissociation protomers. Idan ware daga dokokin subunits na Camp DNA, da furotin da kinase m hadaddun sake mayar da su a tetramer, kamar yadda ya auku Association catalytic da tsaiko peptide barbashi. Saboda haka, hanyar da tsari na enzyme aiki tattauna a sama samar da su reversible yanayi.

Chemical tsari na enzyme aiki

Biochemistry da karatu wadannan sunadaran da tsari na enzyme aiki, phosphorylation, dephosphorylation. Ginshikai na tsari na enzyme aiki a wannan yanayin yana da wadannan nau'i: amino acid sharan na enzyme dauke da OH ^-, canza su sinadaran gyara saboda daukan hotuna zuwa fosfoproteinfosfataz. A wannan yanayin, gyara amenable zuwa da aiki site na enzyme, cikinsa da enzymes saboda wasu dalilai da shi ne kunna su, kuma don wasu - mai hanawa. fosfoproteinfosfataz catalytic kaddarorin da kansu suke kayyade hormones bi da bi. Alal misali, dabba sitaci - glycogen - da kuma kitse a tsakanin abinci suna karye a cikin gastrointestinal fili, ko fiye daidai, a cikin duodenum ƙarƙashin rinjayar glucagon - pancreatic enzyme.

Wannan tsari ne da inganta ta phosphorylation na trophic gastrointestinal enzymes. A cikin aiki tsawon narkewa a lokacin da abinci ya shiga daga ciki a cikin duodenum, glucagon kira da aka inganta. Insulin - daya pancreatic enzyme samar da alpha Kwayoyin na tun fil azal, na Langerhans, - interacts tare da tsoka mai amsa sigina, ciki har da phosphorylation na wannan inji na narkewa kamar enzymes.

m proteolysis

Kamar yadda ka gani, matakan da tsari na enzyme aiki a cikin cell bambanta. Domin enzymes da suke waje da cytosol ko wasu gabbansa (a cikin jini jini ko a cikin gastrointestinal fili), da hanyar da kunnawa ne tsari na hydrolysis da peptide bond CO-NH. Yana ake bukata, tun da irin wannan enzymes an hada a wani m form. Kwayar Komayya aka cleaved ta enzyme peptide rabo da saura shi ne batun gyara daga cikin tsarin da aiki site. Wannan take kaiwa zuwa gaskiya cewa enzyme "ya hada da wani aiki yanayin", wato, shi ne iya tasiri cikin shakka daga cikin tsarin sunadarai. Alal misali, m enzyme pancreatic trypsinogen ba cleaves sunadaran abinci shigar da duodenum. Yana daukan wuri a karkashin mataki na enteropeptidase proteolysis. Bayan da aka kunna enzyme da yanzu ake kira trypsin. M proteolysis - da tsari ne reversible. Yana auku a lokuta kamar kunnawa da enzymes cewa karya saukar polypeptides a jini clotting.

Aikin taro na fara kayan a cikin cell metabolism

Regulation da ayyuka na enzyme substrate kasancewa kyan gani, jera a cikin contact subtitle "multienzyme hadaddun." A kudi na catalytic halayen faruwa a dama, saukarwa, shi ne sosai dogara a kan yawan kwayoyin na fara abu ne a hyaloplasm Kwayoyin ko wasu gabbansa. Wannan shi ne saboda cewa da gudun da rayuwa hanya ne kai tsaye na gwargwado ga taro na fara abu. A ya fi girma reactant kwayoyin dake a cikin cytosol, da hakan gudun duk m sinadaran halayen.

allosteric tsari

Enzymes wanda aiki ne sarrafawa ba kawai ta maida hankali na fara kayan, reagents, amma kuma da effector abubuwa, halin da haka ya kira allosteric tsari. Yawancin wadannan enzymes an gabatar da matsakaiciyar kayayyakin da metabolism a cikin cell. Saboda da effectors da kuma aiwatar da tsari na enzyme aiki. Biochemistry nuna cewa wadannan mahadi, kira allosteric enzymes ne da muhimmanci sosai ga metabolism na Kwayoyin, kamar yadda suke da wani musamman high ji na ƙwarai to canje-canje a cikin homeostasis. Idan enzyme damuarn da sinadaran dauki, watau shi na rage gudun - shi ne ake kira mai korau effector (hanawa). A daura da haka al'amarin, idan akwai wata karuwa a dauki kudi, ya zo ga activator - mai kyau effector. A mafi yawan lokuta da fara kayan, Ina nufin reactants shiga sinadaran interactions taka rawa activators. Hakika, da kayayyakin kafa ta multistage halayen nuna hali a matsayin mai hanawa. Wannan irin tsari gina a kan dangantakar da taro na reactants da kuma kayayyakin, da ake kira heterotrophic.