Proteins, lub luag haujlwm lom neeg uas yuav raug txiav txim siab hnub no, yog macromolecular compounds tsim los ntawm cov amino acids. Ntawm tag nrho lwm cov organic tebchaw, lawv yog cov nyuaj tshaj plaws hauv lawv cov qauv. Raws li lub hauv paus muaj pes tsawg leeg, cov protein sib txawv ntawm cov rog thiab carbohydrates: ntxiv rau oxygen, hydrogen thiab carbon, lawv kuj muaj nitrogen. Tsis tas li ntawd, sulfur yog ib qho tseem ceeb ntawm cov proteins uas tseem ceeb tshaj plaws, thiab qee qhov muaj iodine, hlau thiab phosphorus.
Lub luag haujlwm lom neeg ntawm cov protein ntau heev. Nws yog cov tebchaw uas ua rau cov loj ntawm protoplasm, nrog rau cov nuclei ntawm cov cell nyob. Proteins muaj nyob rau hauv tag nrho cov tsiaj thiab nroj tsuag kab mob.
Ib lossis ntau lub luag haujlwm
Lub luag haujlwm lom neeg thiab kev ua haujlwm ntawm lawv cov tebchaw sib txawv sib txawv. Raws li cov khoom siv nrog cov qauv tshuaj tshwj xeeb, txhua cov protein ua haujlwm tshwj xeeb heev. Tsuas yog qee qhov nws tuaj yeem ua tau ntau qhov sib cuam tshuam ib zaug. Piv txwv li, adrenaline, uas yog tsim nyob rau hauv lub medullaqog adrenal, nkag mus rau hauv cov hlab ntsha, nce ntshav siab thiab oxygen noj, ntshav qab zib. Tsis tas li ntawd, nws yog ib qho stimulant ntawm cov metabolism, thiab nyob rau hauv cov tsiaj ntshav txias nws kuj yog ib tug nruab nrab ntawm lub paj hlwb. Raws li koj tuaj yeem pom, nws ua tau ntau yam haujlwm ib zaug.
Enzymatic (catalytic) muaj nuj nqi
Ntau yam tshuaj lom neeg biochemical tshwm sim hauv cov kab mob muaj sia tau ua nyob rau hauv cov xwm txheej me, uas qhov kub thiab txias yog ze rau 40 ° C, thiab pH qhov tseem ceeb yuav luag nruab nrab. Nyob rau hauv cov xwm txheej no, tus nqi ntws ntawm ntau ntawm lawv yog negligible. Yog li ntawd, txhawm rau kom lawv paub tseeb, cov enzymes xav tau - tshwj xeeb lom catalysts. Yuav luag tag nrho cov tshuaj tiv thaiv, tshwj tsis yog rau cov dej photolysis, yog catalyzed hauv cov kab mob uas muaj sia nyob los ntawm cov enzymes. Cov ntsiab lus no yog cov proteins lossis complexes ntawm cov proteins nrog cofactor (organic molecule lossis hlau ion). Enzymes ua ntau yam xaiv, pib cov txheej txheem tsim nyog. Yog li, lub luag haujlwm catalytic tau tham saum toj no yog ib qho ntawm cov proteins ua. Lub luag haujlwm lom neeg ntawm cov tebchaw no, txawm li cas los xij, tsis txwv rau nws qhov kev siv. Muaj ntau yam ntxiv uas peb yuav saib hauv qab no.
Kev thauj khoom muaj nuj nqi
Rau lub neej ntawm tes, nws yog ib qho tsim nyog kom muaj ntau yam khoom nkag mus rau hauv nws, uas muab lub zog thiab cov khoom siv hauv tsev. Txhua daim nyias nyias yog tsim nyob rau hauv ib qhotxoj cai. Qhov no yog ob txheej ntawm lipids, cov protein yog immersed nyob rau hauv nws. Nyob rau tib lub sijhawm, thaj chaw hydrophilic ntawm macromolecules yog concentrated nyob rau saum npoo ntawm daim nyias nyias, thiab hydrophobic "tails" yog concentrated nyob rau hauv lawv thickness. Cov qauv no tseem tsis tau nkag mus rau cov khoom tseem ceeb: amino acids, suab thaj, alkali hlau ions. Kev nkag mus ntawm cov ntsiab lus no mus rau hauv lub cell tshwm sim nrog kev pab los ntawm kev thauj cov proteins uas yog embedded nyob rau hauv lub cell membrane. Cov kab mob, piv txwv li, muaj cov protein tshwj xeeb uas thauj cov lactose (mis qab zib) hla cov txheej txheem sab nrauv.
Multicellular organisms muaj lub cev thauj ntau yam khoom ntawm ib lub cev mus rau lwm qhov. Peb tab tom tham feem ntau txog hemoglobin (daim duab saum toj no). Tsis tas li ntawd, serum albumin (transport protein) muaj nyob rau hauv cov ntshav plasma tas li. Nws muaj peev xwm tsim cov complexes muaj zog nrog fatty acids tsim thaum lub sij hawm zom cov rog, nrog rau ntau cov hydrophobic amino acids (piv txwv li, nrog tryptophan) thiab nrog ntau yam tshuaj (qee yam penicillins, sulfonamides, aspirin). Transferrin, uas kho kom haum rau kev thauj cov hlau ions hauv lub cev, yog lwm qhov piv txwv. Peb kuj tuaj yeem hais txog ceruplasmin, uas nqa tooj liab ions. Yog li, peb tau txiav txim siab txog kev thauj mus los uas cov protein ua. Lawv lub luag haujlwm lom neeg kuj tseem ceeb heev los ntawm qhov kev pom no.
Receptor muaj nuj nqi
Receptor proteins yog qhov tseem ceeb heev, tshwj xeeb tshaj yog rau kev txhawb nqa lub neej ntawm ntau cov kab mob. Lawv nyob nraum ua nyob rau hauvmus rau hauv lub plasma cell membrane thiab pab rau perceive thiab ntxiv hloov cov teeb liab uas nkag mus rau hauv lub cell. Hauv qhov no, cov cim qhia tuaj yeem yog los ntawm lwm lub hlwb thiab los ntawm ib puag ncig. Acetylcholine receptors yog tam sim no kawm tshaj plaws. Lawv nyob rau hauv ib tug xov tooj ntawm interneuronal hu rau ntawm lub cell membrane, nrog rau ntawm cov neuromuscular junctions, nyob rau hauv lub cerebral cortex. Cov proteins no cuam tshuam nrog acetylcholine thiab xa cov teeb liab mus rau hauv lub cell.
Lub neurotransmitter kom tau txais lub teeb liab thiab hloov nws yuav tsum raug tshem tawm kom lub cell muaj lub sijhawm los npaj rau kev nkag siab ntawm cov teeb liab ntxiv. Rau qhov no, acetylcholinesterase yog siv - ib qho tshwj xeeb enzyme uas catalyzes hydrolysis ntawm acetylcholine rau choline thiab acetate. Puas yog nws tsis muaj tseeb tias qhov kev ua haujlwm receptor uas cov protein ua tau tseem ceeb heev? Lub luag haujlwm lom neeg ntawm lub neej tom ntej, kev tiv thaiv kev ua haujlwm rau lub cev yog loj heev. Ib qho yooj yim tsis pom zoo rau qhov no.
tiv thaiv muaj nuj nqi
Nyob rau hauv lub cev, lub cev tiv thaiv kab mob teb rau cov tsos ntawm txawv teb chaws hais nyob rau hauv nws los ntawm tsim ib tug loj tus naj npawb ntawm lymphocytes. Lawv muaj peev xwm ua kom puas cov ntsiab lus xaiv. Xws li cov khoom txawv teb chaws tuaj yeem yog cov kab mob qog noj ntshav, cov kab mob pathogenic, cov kab mob supramolecular (macromolecules, kab mob, thiab lwm yam). B-lymphocytes yog ib pawg ntawm lymphocytes uas tsim cov protein tshwj xeeb. Cov proteins no raug tso tawm rau hauv cov hlab ntsha. Lawv paub txog cov khoom txawv teb chaws, thaum tsim ib qho chaw tshwj xeeb ntawm kev puas tsuaj. Cov proteins no hu ua immunoglobulins. Cov khoom txawv teb chaws hu ua antigens.uas ua rau lub cev tiv thaiv kab mob.
Structural function
Dhau li ntawm cov proteins uas ua haujlwm tshwj xeeb, tseem muaj cov uas nws qhov tseem ceeb yog cov qauv tsim. Ua tsaug rau lawv, txhua yam muaj zog yog muab, nrog rau lwm yam khoom ntawm cov ntaub so ntswg ntawm cov kab mob nyob. Cov proteins no suav nrog, ua ntej ntawm tag nrho, collagen. Collagen (daim duab hauv qab no) nyob rau hauv cov tsiaj muaj li ib feem peb ntawm cov protein ntau. Nws yog synthesized nyob rau hauv lub ntsiab hlwb uas ua li connective cov ntaub so ntswg (hu ua fibroblasts).
Thaum pib, collagen yog tsim los ua procollagen - nws cov precursor, undergoing chemical processing nyob rau hauv fibroblasts. Tom qab ntawd nws yog tsim nyob rau hauv daim ntawv ntawm peb polypeptide chains twisted rau hauv ib tug kauv. Lawv ua ke twb sab nraum lub fibroblasts rau hauv collagen fibrils ob peb puas nanometers nyob rau hauv txoj kab uas hla. Cov tom kawg daim ntawv collagen filaments, uas twb tau pom nyob rau hauv ib tug microscope. Nyob rau hauv cov ntaub so ntswg elastic (phab ntsa ntawm lub ntsws, hlab ntsha, daim tawv nqaij), extracellular matrix, ntxiv rau collagen, kuj muaj cov protein elastin. Nws tuaj yeem ncav cuag qhov dav dav thiab tom qab ntawd rov qab mus rau nws qhov qub qub. Lwm qhov piv txwv ntawm cov qauv protein uas tuaj yeem muab tau ntawm no yog silk fibroin. Nws raug cais tawm thaum tsim cov pupa ntawm silkworm kab ntsig. Nws yog cov khoom tseem ceeb ntawm cov xov paj ntaub. Wb mus rau qhov piav qhia ntawm lub cev muaj zog proteins.
Motor proteins
Thiab hauv kev siv cov txheej txheem lub cev muaj zog, lub luag haujlwm lom neeg ntawm cov protein yog qhov zoo. Cia peb tham luv luv txog qhov haujlwm no. Cov leeg nqaij contraction yog cov txheej txheem thaum lub sij hawm tshuaj lom neeg lub zog hloov mus rau hauv txhua yam kev ua haujlwm. Nws cov neeg koom ncaj qha yog ob qho proteins - myosin thiab actin. Myosin muaj cov qauv txawv txawv heev. Nws yog tsim los ntawm ob lub taub hau globular thiab tus Tsov tus tw (ib ntu ntev filamentous). Txog 1600 nm yog qhov ntev ntawm ib lub molecule. Lub taub hau account rau kwv yees li 200 nm.
Actin (daim duab saum toj no) yog globular protein uas muaj qhov hnyav ntawm molecular ntawm 42,000. Nws tuaj yeem polymerize los ua cov qauv ntev thiab sib cuam tshuam hauv daim ntawv no nrog lub taub hau myosin. Ib qho tseem ceeb ntawm cov txheej txheem no yog nws qhov kev vam khom ntawm lub xub ntiag ntawm ATP. Yog tias nws cov concentration siab txaus, cov complex tsim los ntawm myosin thiab actin raug rhuav tshem, thiab tom qab ntawd nws rov qab los dua tom qab ATP hydrolysis tshwm sim los ntawm kev ua ntawm myosin ATPase. Cov txheej txheem no tuaj yeem pom, piv txwv li, nyob rau hauv ib qho kev daws teeb meem uas muaj ob qho proteins. Nws ua viscous vim qhov tsim ntawm qhov hnyav molecular hnyav hauv qhov tsis muaj ATP. Thaum nws ntxiv, viscosity txo qis vim kev puas tsuaj ntawm cov tsim complex, tom qab ntawd nws maj mam pib rov qab los ntawm ATP hydrolysis. Hauv cov txheej txheem ntawm cov leeg nqaij, cov kev sib cuam tshuam no ua lub luag haujlwm tseem ceeb.
Tshuaj tua kab mob
Peb txuas ntxiv nthuav tawm lub ntsiab lus "Lub luag haujlwm lom neeg ntawm cov protein hauv lub cev." Ib pawg loj thiab tseem ceeb heevnatural compounds tsim cov tshuaj hu ua tshuaj tua kab mob. Lawv yog cov kab mob microbial. Cov tshuaj no yog secreted los ntawm tshwj xeeb hom kab mob. Lub luag haujlwm lom neeg ntawm cov amino acids thiab cov proteins yog qhov tsis txaus ntseeg, tab sis cov tshuaj tua kab mob ua haujlwm tshwj xeeb, tseem ceeb heev. Lawv inhibit qhov kev loj hlob ntawm cov kab mob uas sib tw nrog lawv. Xyoo 1940, kev tshawb nrhiav thiab siv tshuaj tua kab mob tau hloov kho cov kab mob sib kis los ntawm cov kab mob. Nws yuav tsum raug sau tseg tias feem ntau, cov tshuaj tua kab mob tsis ua haujlwm rau cov kab mob, yog li siv lawv li cov tshuaj tiv thaiv kab mob tsis zoo.
Piv txwv tshuaj tua kab mob
Pab pawg penicillin yog thawj zaug muab tso rau hauv kev xyaum. Piv txwv ntawm pab pawg no yog ampicillin thiab benzylpenicillin. Cov tshuaj tua kab mob muaj ntau yam hauv lawv cov txheej txheem ntawm kev ua thiab tshuaj lom neeg. Qee cov uas tau siv dav niaj hnub no cuam tshuam nrog tib neeg ribosomes, thaum cov protein synthesis yog inhibited hauv cov kab mob ribosomes. Nyob rau tib lub sijhawm, lawv tsis tshua cuam tshuam nrog eukaryotic ribosomes. Yog li ntawd, lawv yog cov puas tsuaj rau cov kab mob hlwb, thiab me ntsis lom rau tsiaj thiab tib neeg. Cov tshuaj tua kab mob no suav nrog streptomycin thiab levomycetin (chloramphenicol).
Lub luag haujlwm lom ntawm cov protein biosynthesis tseem ceeb heev, thiab cov txheej txheem no nws tus kheej muaj ntau theem. Peb tsuas yog tham txog nws hauv cov ntsiab lus dav dav.
txheej txheem thiab lub luag haujlwm lom neeg ntawm cov protein biosynthesis
txheej txheem no yog ntau kauj ruam thiab nyuaj heev. Nws tshwm sim hauv ribosomes -tshwj xeeb organelles. Lub cell muaj ntau ribosomes. Piv txwv li, E. coli muaj txog 20 txhiab ntawm lawv.
"Qhia txog cov txheej txheem ntawm cov protein biosynthesis thiab nws txoj haujlwm lom neeg" - xws li ib txoj haujlwm uas peb tau txais hauv tsev kawm ntawv. Thiab rau ntau nws tau nyuaj. Zoo, cia peb sim ua kom tiav ua ke.
Protein molecules yog polypeptide chains. Lawv muaj, raws li koj twb paub lawm, ntawm tus kheej cov amino acids. Txawm li cas los xij, tom kawg tsis muaj zog txaus. Txhawm rau ua ke thiab tsim cov protein molecule, lawv yuav tsum ua kom muaj zog. Nws tshwm sim los ntawm kev ua haujlwm ntawm cov enzymes tshwj xeeb. Txhua amino acid muaj nws tus kheej enzyme tshwj xeeb tuned rau nws. Lub zog qhov chaw rau cov txheej txheem no yog ATP (adenosine triphosphate). Raws li kev ua kom muaj zog, cov amino acid ua ntau labile thiab khi nyob rau hauv qhov kev txiav txim ntawm cov enzyme no rau t-RNA, uas hloov nws mus rau ribosome (vim qhov no, RNA no hu ua thauj). Yog li, activated amino acids txuas nrog tRNA nkag mus rau ribosome. Lub ribosome yog ib hom conveyor rau assembling protein chains los ntawm cov amino acids.
Lub luag haujlwm ntawm cov protein synthesis yog qhov nyuaj rau overestimate, vim tias cov synthesized compounds ua haujlwm tseem ceeb heev. Yuav luag tag nrho cov qauv cellular yog tsim los ntawm lawv.
Yog li, peb tau piav qhia dav dav txog cov txheej txheem ntawm cov protein biosynthesis thiab nws lub luag haujlwm lom neeg. Qhov no xaus peb cov lus qhia txog cov proteins. Peb vam tias koj muaj lub siab xav mus ntxiv.
