Cov qauv thiab kev ua haujlwm ntawm cov protein
Pendahuluuan
Cov protein yog cov molecule loj, nyuaj uas ua lub luag haujlwm tseem ceeb hauv yuav luag txhua txoj kev ua haujlwm ntawm tib neeg thiab lwm yam tsiaj txhu. Lawv muaj cov saw ntev ntawm cov amino acids uas muab tais ua cov duab peb-seem tshwj xeeb, ua rau lawv ua ntau yam haujlwm. Hauv tsab xov xwm no, peb yuav tshawb nrhiav cov qauv protein, cov hom qauv uas muaj, thiab ntau yam haujlwm ntawm cov protein hauv lub cev.
Cov qauv protein
Cov qauv ntawm cov protein muaj plaub theem tseem ceeb: theem pib, theem nrab, theem peb, thiab theem plaub. Txhua theem no muab kev nkag siab txog seb cov protein raug tsim thiab ua haujlwm li cas.
1. Cov Qauv Tseem Ceeb
Cov qauv tseem ceeb ntawm cov protein yog cov kab sib law liag ntawm cov amino acids uas tau teeb tsa raws li cov lus qhia los ntawm DNA. Txhua cov protein muaj cov kab sib law liag tshwj xeeb ntawm cov amino acids uas txiav txim siab nws cov khoom siv tshuaj lom neeg. Cov kab sib law liag no txuas nrog los ntawm cov peptide bonds, uas tau tsim los ntawm kev sib xyaw ua ke ntawm pawg carboxyl ntawm ib qho amino acid thiab pawg amino ntawm qhov tom ntej. Cov kab sib law liag amino acid no tseem ceeb heev vim nws txiav txim siab cov qauv peb-seem thiab kev ua haujlwm tag nrho ntawm cov protein.
2. Cov Qauv Thib Ob
Cov qauv theem ob ntawm cov protein yog cov qauv folding uas tsim los ntawm kev sib cuam tshuam ntawm cov atoms hauv polypeptide backbone. Muaj ob hom tseem ceeb ntawm cov qauv theem ob: alpha helix thiab beta sheet. Alpha helix yog cov qauv kauv uas tswj hwm los ntawm hydrogen bonds ntawm txhua amino acid thiab plaub amino acid raws li saw. Beta sheet, ntawm qhov tod tes, yog ib daim ntawv tiaj tiaj uas tuav ua ke los ntawm hydrogen bonds ntawm cov polypeptide chains uas nyob ib sab. Cov qauv no muab kev ruaj khov ntxiv rau cov protein.
3. Cov Qauv Qib Peb
Cov qauv tertiary yog hais txog tag nrho cov duab peb-seem ntawm ib qho polypeptide, uas yog los ntawm kev sib cuam tshuam ntawm cov saw hlau sab (R-pawg) ntawm cov amino acids. Cov kev sib cuam tshuam no suav nrog hydrogen bonds, ionic bonds, disulfide bonds, thiab hydrophobic interactions. Cov qauv tertiary yog qhov tseem ceeb vim nws txiav txim siab txog kev ua haujlwm ntawm cov protein. Piv txwv li, cov enzymes muaj cov chaw tshwj xeeb uas tsuas yog tuaj yeem paub los ntawm cov substrates tshwj xeeb, uas tso cai rau cov tshuaj tiv thaiv kom ua tiav zoo.
4. Cov Qauv Quaternary
Cov qauv Quaternary yog qib siab dua ntawm kev teeb tsa protein thiab cuam tshuam nrog kev sib xyaw ua ke ntawm ntau dua ib txoj saw polypeptide. Txhua txoj saw hauv cov qauv no hu ua subunit, thiab lawv tuaj yeem sib cuam tshuam los ntawm ntau hom kev sib txuas tshuaj lom neeg. Ib qho piv txwv zoo ntawm cov protein nrog cov qauv quaternary yog hemoglobin, uas muaj plaub lub polypeptide subunits. Kev sib cuam tshuam ntawm cov subunits no tso cai rau cov protein ua cov haujlwm tshwj xeeb xws li kev khi oxygen.
Kev Ua Haujlwm ntawm Protein
Cov protein muaj ntau yam haujlwm hauv cov tsiaj txhu uas muaj sia nyob, qee qhov tseem ceeb rau kev ciaj sia. Nov yog qee qhov haujlwm tseem ceeb ntawm cov protein:
1. Enzymatic
Cov enzymes yog cov protein uas ua haujlwm ua cov catalysts hauv cov tshuaj lom neeg. Lawv ua kom cov tshuaj lom neeg sai dua yam tsis hloov pauv tas mus li. Piv txwv ntawm cov enzymes suav nrog amylase, uas rhuav cov hmoov txhuv nplej siab ua cov suab thaj yooj yim, thiab DNA polymerase, uas koom nrog DNA replication. Yog tsis muaj enzymes, ntau yam tshuaj lom neeg tseem ceeb yuav tshwm sim qeeb heev lossis tsis tshwm sim li.
2. Kev Tsim Kho
Cov protein uas muaj cov qauv muab kev txhawb nqa lub cev thiab cov duab rau cov cell, cov nqaij, thiab cov kab mob tag nrho. Piv txwv ntawm cov protein uas muaj cov qauv suav nrog collagen, cov protein tseem ceeb hauv cov nqaij sib txuas xws li daim tawv nqaij, pob txha, thiab cov leeg, thiab keratin, uas tsim cov plaub hau, cov rau tes, thiab txheej sab nraud ntawm daim tawv nqaij. Cov protein no muab lub zog thiab elasticity tsim nyog los tiv taus ntau yam kev ntxhov siab ntawm lub cev.
3. Kev Thauj Mus Los thiab Kev Khaws Cia
Qee cov protein ua haujlwm thauj cov molecules tseem ceeb hauv lub cev. Piv txwv li, hemoglobin yog lub luag haujlwm thauj cov pa oxygen los ntawm lub ntsws thoob plaws lub cev. Lwm cov protein, xws li ferritin, khaws cov hlau rau hauv cov cell thiab tso nws tawm thaum xav tau. Qhov kev thauj mus los no tseem ceeb heev rau kev tswj hwm kev ua haujlwm ntawm cell thiab cov xwm txheej ntawm lub cev.
4. Kev Tswj Xyuas
Cov protein kuj tseem tuaj yeem ua lub luag haujlwm hauv kev tswj cov txheej txheem biochemical thiab physiological. Cov tshuaj hormones xws li insulin yog cov protein uas tswj cov ntshav qab zib los ntawm kev pab txhawb kev nqus cov piam thaj los ntawm cov cell. Tsis tas li ntawd, cov transcription factors yog cov protein uas tswj kev qhia tawm ntawm cov noob tshwj xeeb, txiav txim siab seb cov protein twg yuav tsum tsim tawm hauv cov cell thaum twg.
5. Kev Tiv Thaiv thiab Kev Tiv Thaiv
Cov protein kuj tseem ua lub luag haujlwm hauv lub cev tiv thaiv kab mob. Cov tshuaj tiv thaiv kab mob yog cov protein uas tsim los ntawm cov qe ntshav B hauv lub cev tiv thaiv kab mob thiab ua haujlwm los paub thiab tshem tawm cov kab mob xws li cov kab mob me me thiab cov kab mob me me. Ntxiv mus, cov protein tiv thaiv xws li fibrinogen ua lub luag haujlwm hauv kev txhaws ntshav, tiv thaiv kev poob ntshav ntau dhau thaum raug mob.
6. Kev Qaug Zog thiab Kev Txav Mus Los
Cov protein kuj tseem ceeb rau kev txav mus los ntawm tes thiab kev sib cog lus. Actin thiab myosin yog cov protein tseem ceeb uas koom nrog kev sib cog lus ntawm cov leeg. Lawv swb dhau ib leeg los tsim cov kev sib cog lus uas ua rau lub cev txav mus los. Tsis tas li ntawd, cov protein xws li dynein thiab kinesin ua lub luag haujlwm hauv kev txav mus los ntawm cov khoom siv tes ua raws li microtubules, uas yog qhov tseem ceeb rau kev faib tawm ntawm organelles thiab vesicles.
Xaus
Zuag qhia tag nrho, cov protein yog cov molecule uas muaj ntau yam siv tau thiab tseem ceeb rau yuav luag txhua yam ntawm lub neej. Txij li lawv cov qauv plaub theem mus rau lawv cov haujlwm uas suav nrog enzymatic, structural, transport, regulatory, defense, thiab locomotion, cov protein ua lub luag haujlwm tseem ceeb hauv kev tswj lub neej thiab cov haujlwm ntawm cov kab mob. Kev nkag siab ntxiv txog cov qauv protein thiab kev ua haujlwm tsis yog tsuas yog qhov tseem ceeb rau kev tshawb fawb tseem ceeb xwb tab sis kuj muaj txiaj ntsig zoo rau kev siv kho mob thiab biotechnological. Kev tshawb fawb txuas ntxiv mus nrhiav pom ntau yam zais cia txog li cas cov protein ua haujlwm, paving txoj hauv kev rau kev tsim kho tshiab hauv ntau qhov chaw ntawm kev tshawb fawb thiab kev noj qab haus huv tib neeg.
