Txhua lub xovtooj ntawm txhua yam kabmob muaj cov qauv uas suav nrog ntau yam.
Qhia txog cov qauv ntawm tes
Nws muaj ib daim nyias nyias, cytoplasm, organelles nyob rau hauv lawv, nrog rau lub nucleus (tshwj tsis yog rau prokaryotes), uas DNA molecules nyob. Tsis tas li ntawd, muaj kev tiv thaiv ntxiv rau saum daim nyias nyias. Nyob rau hauv cov tsiaj hlwb nws yog glycocalyx, nyob rau hauv tag nrho lwm yam nws yog lub cell phab ntsa. Hauv cov nroj tsuag, nws muaj cellulose, nyob rau hauv fungi - ntawm chitin, nyob rau hauv cov kab mob - ntawm murein. Lub membrane muaj peb txheej: ob phospholipids thiab protein ntawm lawv.
Nws muaj qhov pores, los ntawm kev hloov cov tshuaj hauv thiab tawm. Nyob ze txhua qhov pore yog cov khoom thauj tshwj xeeb uas tso cai rau qee yam khoom nkag mus rau hauv lub cell. Cov organelles ntawm cov tsiaj cell yog:
- mitochondria, uas ua raws li ib yam ntawm "cov nroj tsuag hluav taws xob" (cov txheej txheem ntawm kev ua pa ntawm tes thiab lub zog sib txuas ua haujlwm nyob rau hauv lawv);
- lysosomes, uas muaj cov enzymes tshwj xeeb rau cov metabolism;
- Golgi complex, tsim los khaws thiab hloov qee yam tshuaj;
- endoplasmic reticulum, uasxav tau rau kev thauj cov tshuaj lom neeg;
- centrosome, muaj ob lub centrioles uas koom nrog hauv kev faib;
- nucleolus, uas tswj cov txheej txheem metabolic thiab tsim qee cov organelles;
- ribosomes, uas peb yuav tham kom ntxaws hauv kab lus no;
- cog hlwb muaj cov organelles ntxiv: lub vacuole, uas yuav tsum tau rau cov tsub zuj zuj ntawm cov khoom tsis tsim nyog vim tsis muaj peev xwm coj lawv tawm vim yog phab ntsa cell muaj zog; plastids, uas yog subdivided rau hauv leukoplasts (lub luag hauj lwm rau khaws cia cov as-ham chemical compounds); chromoplasts muaj cov xim zoo nkauj; chloroplasts, uas muaj chlorophyll thiab qhov chaw photosynthesis tshwm sim.
YLub ribosome yog dab tsi?
Vim peb tab tom tham txog nws hauv kab lus no, nws yog qhov tsim nyog los nug cov lus nug no. Lub ribosome yog ib qho organelle uas tuaj yeem nyob rau sab nrauv ntawm phab ntsa ntawm Golgi complex. Nws tseem yuav tsum tau muab sau tseg tias ribosome yog ib qho organelle uas muaj nyob rau hauv lub cell nyob rau hauv ntau heev. Ib qho tuaj yeem muaj txog li kaum txhiab.
Cov kab mob no nyob qhov twg?
Yog li, raws li twb tau hais lawm, ribosome yog cov qauv uas nyob rau ntawm phab ntsa ntawm Golgi complex. Nws tseem tuaj yeem txav mus los hauv cytoplasm. Qhov thib peb xaiv qhov twg ribosome tuaj yeem nyob yog lub cell membrane. Thiab cov organelles uas nyob rau hauv qhov chaw no xyaum tsis tawm nws thiab nyob twj ywm.
Ribosome - structure
HowQhov no organelle zoo li cas? Nws zoo li lub xov tooj nrog lub receiver. Lub ribosome ntawm eukaryotes thiab prokaryotes muaj ob ntu, ib qho loj dua, lwm qhov yog me dua. Tab sis ob feem ntawm nws tsis koom ua ke thaum nws nyob twj ywm. Qhov no tshwm sim tsuas yog thaum ribosome ntawm lub cell ncaj qha pib ua nws txoj haujlwm. Peb mam li tham txog cov haujlwm tom qab. Lub ribosome, tus qauv uas tau piav qhia hauv tsab xov xwm, kuj muaj tus xa xov RNA thiab hloov RNA. Cov tshuaj no yog tsim nyog los sau rau lawv cov ntaub ntawv hais txog cov proteins uas xav tau los ntawm lub cell. Lub ribosome, cov qauv uas peb tab tom xav txog, tsis muaj nws tus kheej daim nyias nyias. Nws subunits (raws li nws ob halves hu ua) tsis muaj kev tiv thaiv los ntawm dab tsi.
Lub cev no ua haujlwm dab tsi hauv lub cell?
Dab tsi lub ribosome yog lub luag haujlwm rau yog protein synthesis. Nws tshwm sim raws li cov ntaub ntawv uas tau sau tseg ntawm tus xa xov RNA (ribonucleic acid). Lub ribosome, cov qauv uas peb soj ntsuam saum toj no, muab nws ob subunits tsuas yog rau lub sij hawm ntawm protein synthesis - ib tug txheej txheem hu ua kev txhais lus. Thaum lub sij hawm cov txheej txheem no, cov synthesized polypeptide saw yog nyob nruab nrab ntawm ob subunits ntawm ribosome.
lawv tsim qhov twg?
Lub ribosome yog ib qho organelle uas tsim los ntawm nucleolus. Cov txheej txheem no tshwm sim nyob rau hauv kaum theem, thaum lub sij hawm uas cov proteins ntawm me thiab loj subunits yog maj mam tsim.
proteins tsim li cas?
Protein biosynthesis tshwm sim hauv ntau theem. Thawj tusyog ua kom cov amino acids. Muaj nees nkaum ntawm lawv tag nrho, thiab los ntawm kev sib txuas nrog ntau txoj kev, koj tuaj yeem tau txais ntau lab ntawm cov protein sib txawv. Thaum lub sijhawm no, amino allic-t-RNA yog tsim los ntawm cov amino acids. Cov txheej txheem no ua tsis tau yog tsis muaj kev koom tes ntawm ATP (adenosine triphosphoric acid). Cov txheej txheem no kuj xav tau magnesium cations.
theem thib ob yog qhov pib ntawm cov saw hlau polypeptide, lossis cov txheej txheem ntawm kev sib txuas ob lub subunits ntawm ribosome thiab muab cov amino acids tsim nyog rau nws. Magnesium ions thiab GTP (guanosine triphosphate) kuj koom nrog hauv cov txheej txheem no. Qhov thib peb theem yog hu ua elongation. Qhov no yog ncaj qha mus rau synthesis ntawm polypeptide saw. tshwm sim los ntawm txoj kev txhais lus. Kev txiav tawm - theem tom ntej - yog cov txheej txheem ntawm kev tawg ntawm cov ribosome mus rau hauv nyias subunits thiab gradual cessation ntawm synthesis ntawm polypeptide saw. Tom ntej no los txog lub xeem theem - thib tsib - yog ua. Nyob rau theem no, cov txheej txheem nyuaj yog tsim los ntawm cov saw yooj yooj yim ntawm cov amino acids, uas twb sawv cev rau cov proteins uas npaj txhij. Cov enzymes tshwj xeeb tau koom nrog hauv cov txheej txheem no, nrog rau cov cofactors.
Protein structure
Txij li thaum ribosome, cov qauv thiab kev ua haujlwm uas peb tau txheeb xyuas hauv kab lus no, yog lub luag haujlwm rau kev sib txuas ntawm cov protein, cia peb saib xyuas lawv cov qauv. Nws yog thawj, theem nrab, tertiary thiab quaternary. Cov qauv tseem ceeb ntawm cov protein yog cov kab ke tshwj xeeb uas cov amino acids uas tsim cov organic compound no nyob. Cov qauv thib ob ntawm cov protein yog tsim los ntawm polypeptidealpha helix chains thiab beta folds. Cov qauv tertiary ntawm cov protein muab rau ib qho kev sib xyaw ntawm alpha helices thiab beta folds. Cov qauv quaternary muaj nyob rau hauv kev tsim ntawm ib qho kev tsim macromolecular. Ntawd yog, kev sib txuas ntawm alpha helices thiab beta qauv tsim globules lossis fibrils. Raws li txoj cai no, ob hom proteins tuaj yeem paub qhov txawv - fibrillar thiab globular.
thawj yog xws li actin thiab myosin, los ntawm cov leeg nqaij tsim. Piv txwv ntawm cov tom kawg yog hemoglobin, immunoglobulin thiab lwm yam. Fibrillar proteins zoo li cov xov, fiber ntau. Globular sawv daws yuav zoo li tangle ntawm alpha helices thiab beta folds woven ua ke.
Dab tsi yog qhov tseeb?
Txhua tus yuav tsum tau hnov lo lus no. Denaturation yog tus txheej txheem ntawm kev rhuav tshem cov qauv ntawm cov protein - thawj quaternary, tom qab ntawd tertiary, thiab tom qab ntawd theem nrab. Qee zaum, kev tshem tawm ntawm cov qauv tseem ceeb ntawm cov protein kuj tshwm sim. Cov txheej txheem no tuaj yeem tshwm sim vim qhov cuam tshuam ntawm cov organic teeb meem ntawm qhov kub thiab txias. Yog li, cov protein denaturation tuaj yeem pom thaum lub qe qe qe. Feem ntau, cov txheej txheem no yog irreversible. Yog li, ntawm qhov kub siab tshaj plaub caug-ob degrees, hemoglobin denaturation pib, yog li hyperthermia hnyav yog qhov ua rau muaj kev phom sij rau lub neej. Protein denaturation rau ib tus neeg nucleic acids tuaj yeem pom thaum lub sijhawm zom zaub mov, thaum lub cev zom cov organic sib xyaw ua kom yooj yim nrog kev pab ntawm enzymes.
Zoo kawg
Lub luag haujlwm ntawm ribosomes yog qhov nyuaj rau overestimate. Lawv yog lub hauv paus rau lub neej ntawm lub cell. Ua tsaug rau cov organelles, nws tuaj yeem tsim cov proteins uas nws xav tau rau ntau yam haujlwm. Organic compounds tsim los ntawm ribosomes tuaj yeem ua lub luag haujlwm tiv thaiv, lub luag haujlwm thauj khoom, lub luag haujlwm catalyst, lub tsev khoom siv rau lub cell, enzymatic, tswj lub luag haujlwm (ntau cov tshuaj hormones muaj cov qauv protein). Yog li, peb tuaj yeem txiav txim siab tias ribosomes ua ib qho tseem ceeb tshaj plaws hauv lub cell. Yog li ntawd, muaj ntau ntau ntawm lawv - lub cell ib txwm xav tau cov khoom tsim los ntawm cov organelles.
