Isibonelo Semibuzo Yengxoxo Ngama-Polymers Emvelo
Ama-polymer emvelo ayizinto ezitholakala ngokwemvelo ezinama-molecule amakhulu akhiwe ngamayunithi amancane abizwa ngokuthi ama-monomers. Lawa ma-polymer adlala indima ebalulekile empilweni yansuku zonke futhi asetshenziswa kabanzi emikhakheni eyahlukene yezimboni, yezemithi, neyezokwelapha. Izibonelo ezivamile zama-polymer emvelo zifaka phakathi i-cellulose, amaprotheni, irabha yemvelo, kanye nama-nucleic acid. Ngezansi, sizoxoxa ngezinkinga eziningana zezibonelo mayelana nama-polymer emvelo ezingasiza ekujuleni ukuqonda kwethu ngalesi sihloko.
Umbuzo 1: Isakhiwo kanye Nomsebenzi Wama-polymer Emvelo
Umbuzo:
I-cellulose namaprotheni kuyizinhlobo ezimbili ezahlukene zama-polymer emvelo. Chaza umehluko wesakhiwo phakathi kwe-cellulose namaprotheni kanye nemisebenzi yawo ezintweni eziphilayo.
Ingxoxo:
I-Struktur:
I-Cellulose iyi-polymer yama-carbohydrate eyakhiwe ngama-monomers e-glucose. I-glucose eku-cellulose ixhunywe ndawonye ngama-bond angu-1,4-β-glycosidic. Isakhiwo se-Cellulose siqondile futhi ama-bond e-hydrogen phakathi kwamaketanga e-glucose ayenza ibe namandla kakhulu futhi imelane nokuwohloka.
Ngakolunye uhlangothi, amaprotheni angama-polymer ama-amino acid akhiwe ngamaketanga amade ama-amino acid axhunywe ngama-peptide bonds. Isakhiwo samaprotheni sihlukaniswe ngamazinga amaningana: okuyinhloko (ukuhlelwa okuqondile kwama-amino acid), okwesibili (isakhiwo se-α-helical noma se-β-sheet esibangelwa ama-hydrogen bonds), okwesithathu (ukugoqeka okuyinkimbinkimbi kakhulu okuthonywa ukusebenzisana phakathi kwamaketanga aseceleni e-amino acid), kanye ne-quaternary (amaketanga phakathi kwamaketanga amaningana e-polypeptide).
Umsebenzi:
I-Cellulose isebenza njengengxenye eyinhloko yesakhiwo sezindonga zamaseli ezitshalo. Inikeza amandla nokunwebeka, isiza izitshalo ukuthi zihlale ziqonde, futhi ivikele amaseli ekulimaleni kwemishini. I-Cellulose isetshenziswa futhi njengento eluhlaza ezimbonini ezifana nephepha, izindwangu, kanye nepulasitiki ebolayo.
Amaprotheni anemisebenzi eyahlukahlukene ezintweni eziphilayo, okuhlanganisa nama-enzyme asheshisa ukusabela kwamakhemikhali, njengezakhi zesakhiwo (isb., i-collagen esikhumbeni nasezicutshini ezixhumene), njengama-hormone alawula imisebenzi eyahlukahlukene yomzimba, njengama-antibodies alwa nezifo, kanye namaprotheni okuthutha ahambisa ama-molecule athile kuwo wonke ama-membrane eseli.
Umbuzo 2: Izakhiwo Ezibonakalayo Nezamakhemikhali Zama-Polymers Emvelo
Umbuzo:
Xoxa ngezakhiwo zomzimba nezamakhemikhali zerabha yemvelo bese uchaza ukuthi ukuqhuma kwe-vulcanization kungazithinta kanjani lezi zakhiwo.
Ingxoxo:
Irabha yemvelo (noma i-latex) iyi-polymer yemvelo enesakhi sayo esiyinhloko i-polyisoprene. Isici esiyinhloko serabha yemvelo ukuqina kwayo, okuvumela ukuthi ibuyele esimweni sayo sokuqala ngemva kokunwetshwa noma ukucindezelwa. Kodwa-ke, irabha yemvelo eluhlaza inobuthakathaka bokuthi isengozini yokushisa okuphezulu, ukushiswa, kanye nokuhuzuka.
Izakhiwo zamakhemikhali zerabha yemvelo zifaka phakathi ukuncibilika kwezithako eziphilayo ezingezona eziphansi kanye nokuchayeka ekushiseni nasekuwohlokeni kokushisa. Isakhiwo sayo esiqondile, esingesona inethiwekhi sivumela ama-molecule ukuthi ashelele komunye nomunye, okwenza irabha yemvelo inameke emazingeni okushisa aphezulu futhi iqhekeke emazingeni okushisa aphansi.
I-Vulcanization inqubo yamakhemikhali esetshenziselwa ukuthuthukisa izakhiwo zerabha yemvelo ngokudala izixhumanisi ezihlanganisa amaketanga e-polymer ngokushisa nge-sulfur. Le nqubo yandisa ukumelana nokuguquguquka, inikeza ukuzinza okungcono kokushisa, kanye nokumelana nokumuncwa kwamanzi namakhemikhali. I-Vulcanization iphinde inciphise ukunamathela kwerabha yemvelo emazingeni okushisa aphezulu futhi yandisa amandla ayo, okwenza irabha evulcanized iqine kakhulu futhi imelane nokuhuzuka.
Umbuzo 3: Ukuhlanganiswa Kwama-polymer Emvelo
Umbuzo:
Kwenzeka kanjani ukuthi i-biosynthesis yamaprotheni ivele emaseli futhi iyini indima ye-RNA kule nqubo?
Ingxoxo:
Inqubo yokwenziwa kwamaprotheni kumaseli ibizwa ngokuthi ukuhumusha, okuyisigaba sokugcina sokubonakaliswa kwezakhi zofuzo. Le nqubo yenzeka kuma-ribosome, ama-organelle abhekene nokwakheka kwamaprotheni, futhi ihilela izinhlobo eziningana ze-RNA: i-mRNA (i-messenger RNA), i-tRNA (i-transfer RNA), kanye ne-rRNA (i-ribosomal RNA).
1. Ukubhalwa phansi:
Inqubo yokwenziwa kwamaprotheni iqala ngokubhalwa phansi, lapho ingxenye ye-DNA ebhala i-gene yeprotheni ethile ikopishwa ibe yi-mRNA. Le nqubo yenzeka ku-nucleus yeseli, bese i-mRNA ephumayo iqhubekela ku-cytoplasm.
2. Ukuhumusha:
Uma i-mRNA ingena ku-cytoplasm, ixhumana nama-ribosome. I-ribosome ihamba ngentambo ye-mRNA, kanti ama-tRNA athwala ama-amino acid ahambisana nama-codon e-mRNA aya kuma-ribosome. I-tRNA ngayinye ine-anticodon ebopha ku-codon ehambisanayo ku-mRNA, okuqinisekisa ukuthi i-amino acid efanele iyengezwa kuchungechunge lwe-polypeptide olukhulayo.
3. Ukuqaliswa:
Inqubo yokuhumusha iqala ngokuqaliswa, lapho i-ribosome ithola i-codon yokuqala (AUG) ku-mRNA. I-tRNA yokuqala ithwala i-methionine, i-amino acid yokuqala ku-polypeptide chain.
4. Ukwelula:
Okulandelayo, inqubo yokwelula inezela ama-amino acid ngayinye ku-polypeptide chain. I-tRNA ephethe i-amino acid elandelayo ingena endaweni ye-A ye-ribosome, bese kwakheka isibopho se-peptide phakathi kwe-amino acid endaweni ye-A kanye ne-amino acid ku-polypeptide chain ekhulayo.
5. Ukuphela:
Inqubo yokuhumusha iphela ngokuphela lapho i-ribosome ifinyelela i-codon yokuma (i-UAA, i-UAG, noma i-UGA) ku-mRNA. Le codon ayibhalisi noma iyiphi i-amino acid, kodwa ibangela ukukhishwa kweketanga le-polypeptide eliqediwe ku-ribosome.
Kuyo yonke le nqubo, i-mRNA isebenza njengohlaka lwe-amino acid sequence kuma-protein, i-tRNA ithwala ama-amino acid afanele ngokusekelwe ku-codon sequence, kanti i-rRNA yakha ingxenye esebenzayo ye-ribosome, ikhuthaza ukwakheka kwama-peptide bonds. Le nqubo ilawulwa kakhulu futhi iqinisekisa ukuthi iphrotheni ephumayo ihambisana nekhodi yezakhi zofuzo equkethwe ku-DNA.
Umbuzo 4: Ama-polymer emvelo empilweni yansuku zonke
Umbuzo:
Nikeza izibonelo ezintathu zokusetshenziswa kwama-polymer emvelo empilweni yansuku zonke bese uchaza izinzuzo zawo uma kuqhathaniswa nama-polymer okwenziwa.
Ingxoxo:
1. I-Cellulose Ephepheni Nasezindwangu:
I-Cellulose isetshenziswa kabanzi embonini yephepha njengento eyinhloko eluhlaza. Embonini yezindwangu, i-cellulose isebenza njengesisekelo sokukhiqizwa kwemicu yemvelo njengokotini. Izinzuzo ze-cellulose kune-polymers zokwenziwa ukuthi zizinzile futhi zibola kalula. I-Cellulose ingabola ngokwemvelo ngaphandle kokungcolisa imvelo, ngokungafani nama-polymers amaningi okwenziwa, athatha amashumi eminyaka kuya emakhulwini eminyaka ukuthi abole.
2. Irabha Yemvelo Emathayini Ezimoto:
Irabha yemvelo isetshenziswa ekukhiqizeni amathayi emoto ngenxa yokuqina kwayo kanye nokumelana nokuguguleka. Izinzuzo zerabha yemvelo kunerabha yokwenziwa zifaka phakathi ukuzinza kwayo okuphezulu kokushisa kanye nekhono layo lokubuyela esimweni sayo sokuqala ngemva kokucindezelwa. Nakuba irabha yokwenziwa nayo inezinhlobo eziningi zokusetshenziswa, irabha yemvelo isasetshenziswa ngenxa yokusebenza kwayo okuphezulu ezimweni ezithile.
3. Amaprotheni Ekudleni Nasemithini:
Amaprotheni afana ne-albumin ne-gelatin asetshenziswa embonini yokudla neyemithi. I-Albumin ingasetshenziswa njengesiqinisi emikhiqizweni yokudla, kuyilapho i-gelatin isetshenziswa kuma-capsules emithi kanye nezithasiselo. Izinzuzo zalawa maprotheni emvelo ukuthi ayakwazi ukuhambisana ne-biocompatibility yawo kanye nekhono lokugaywa nokucutshungulwa ngumzimba, ngokungafani namanye ama-polymers okwenziwa, angabangela imiphumela emibi noma ukusabela kokungezwani komzimba.
Ama-polymer emvelo anikeza izinzuzo ezibalulekile ekuvumelaneni kwemvelo kanye nokusimama, okunciphisa ukuthembela kumakhemikhali angangcolisa futhi alimaze imvelo. Ukusetshenziswa okuqhubekayo kanye nokuthuthukiswa kwama-polymer emvelo kusekela nomnotho osekelwe kumithombo enobungani nemvelo, ovuselelekayo.
Isiphetho
Ama-polymer emvelo ayizinto ezibalulekile ezicini ezahlukene zokuphila nobuchwepheshe. Ngokuqonda izakhiwo zawo, isakhiwo, i-biosynthesis, kanye nokusetshenziswa kwawo, singahlola ngokujulile izinzuzo kanye nokusetshenziswa okungenzeka kwama-polymer emvelo emikhakheni ehlukahlukene. Ukuzibandakanya ekufundeni ngezivivinyo zokuzijwayeza, njengalezo okuxoxwe ngazo ngenhla, kungaqinisa ukuqonda kwethu kanye nokusetshenziswa okusebenzayo kwama-polymer emvelo empilweni yethu yansuku zonke.
