Ama-virus ayizinto ezithelelanayo ezincane kakhulu ezingazalana ngaphakathi kwamaseli aphilayo kuphela. Angabantu abahlukile, abahlukile kwezinye izinto eziphilayo, ngoba abanaso isakhiwo samaseli noma i-metabolism yabo futhi bathembele ngokuphelele kumnikazi ukuze baphindaphindeke. Ukuqonda ama-virus kuhilela ulwazi ngesakhiwo sawo, izinhlobo, imijikelezo yokuphila, kanye nomthelela ezintweni eziphilayo kanye nendawo ezungezile.
Isakhiwo segciwane
Ngokuvamile, amagciwane aqukethe izingxenye ezimbili eziyinhloko: i-nucleic acid kanye ne-capsid. I-viral nucleic acid ingaba yi-DNA noma i-RNA, ephethe ulwazi lwezakhi zofuzo oludingekayo ukukhiqiza izinhlayiya ezintsha zegciwane. Uhlobo lwe-nucleic acid lunquma izici eziningi zebhayoloji yegciwane, okuhlanganisa nendlela ezithelela ngayo amaseli futhi ziphindaphindeke.
I-capsid iyi-protein coat ezungeze i-nucleic acid futhi iyivikele ekulimaleni. I-capsid idlala indima ebalulekile ekuqapheleni nasekubopheni amaseli abambe iqhaza. Isakhiwo se-Capsid singahluka kakhulu phakathi kwamagciwane ahlukene, kusukela ku-icosahedral (isiyingi esakhiwe ngonxantathu abancane) kuya ku-helical (i-spiral).
Amanye amagciwane anesendlalelo esengeziwe esibizwa ngokuthi i-envelope, esakhiwe ngama-lipid namaprotheni. Le envelope ivame ukutholakala ku-membrane yeseli lomnikazi, igciwane eliyitholile ngesikhathi likhishwa kuseli lomnikazi. Amaprotheni akule envelope avame ukusiza igciwane ukuthi libone futhi lithelele amangqamuzana athile omnikazi.
Izinhlobo zama-virus
Ama-virus angahlukaniswa ngokusekelwe ezindinganisweni ezahlukene, okuhlanganisa uhlobo lwe-nucleic acid athwalayo, ukuma kwe-capsid yawo, ukuba khona noma ukungabikho kwe-envelope, kanye nomjikelezo wawo wokuphila. Nazi ezinye zezinhlobo eziyinhloko zama-virus:
- Igciwane le-DNA: Leli gciwane line-nucleic acid ngesimo se-DNA. Izibonelo zamagciwane e-DNA zifaka phakathi ama-adenovirus, abangela izifo zokuphefumula, kanye namagciwane e-herpes simplex, abangela i-herpes.
- Amagciwane e-RNA: Amagciwane aqukethe i-nucleic acid ngesimo se-RNA. Izibonelo zifaka phakathi amagciwane omkhuhlane, abangela umkhuhlane, kanye nama-coronavirus, abangela i-COVID-19.
- I-Retrovirus: Amagciwane e-RNA asebenzisa i-enzyme ekhethekile ebizwa ngokuthi i-reverse transcriptase ukuguqula i-RNA yawo ibe yi-DNA ngemva kokutheleleka iseli. Isibonelo yi-HIV, ebangela i-AIDS.
- I-bacteriophage: Amagciwane athelela amagciwane. Anomjikelezo wokuphila oyingqayizivele futhi avame ukusetshenziswa njengamathuluzi ocwaningweni lwebhayoloji yama-molecule.
Umjikelezo Wokuphila Kwegciwane
Umjikelezo wokuphila kwegciwane uhilela izigaba eziningana eziyinhloko: ukunamathela, ukungena, ukuphindaphindeka, ukuhlanganiswa, kanye nokukhululwa.
- Okunamathiselwe: Amagciwane ayaqaphela futhi anamathele kuma-receptor athile ebusweni bamaseli amukelayo. Le nqubo ikhetha kakhulu futhi inquma ukuthi yimaphi amukelayo igciwane elingawathelela.
- Ukungena: Ngemva kokunamathela, igciwane noma izakhi zalo zofuzo zingena esitokisini somsingathi. Le nqubo ingabandakanya ukuhlanganiswa kwe-virus envelope ne-host cell membrane noma i-endocytosis, lapho iseli lomsingathi ligwinya igciwane.
- Ukuphindaphinda kanye Nokwenziwa: Uma isingaphakathi kweseli eliyibambayo, i-viral nucleic acid iqondisa iseli ukuthi likhiqize izingxenye ezintsha zegciwane. Lokhu kuhlanganisa ukuphindaphindwa kwe-viral nucleic acid kanye nokuhlanganiswa kwamaprotheni egciwane yimishini yeselula yoyibambayo.
- Ukuhlanganiswa: Izingxenye zegciwane ezisanda kuhlanganiswa zihlanganiswa zibe yizinhlayiya ezintsha zegciwane esitokisini somsingathi.
- Ukukhishwa: Izinhlayiya ezintsha zegciwane ziyakhishwa esitokisini esiphethe, okuvame ukuholela ekufeni noma ekubhujisweni kweseli eliphethe. Amagciwane amboziwe avame ukuthola indawo yawo phakathi nalesi sigaba, ngokuthatha ingxenye yelwelwesi leseli eliphethe.
Umthelela Wamagciwane Ezintweni Eziphilayo
Ama-virus angathelela izinhlobo eziningi zezinto eziphilayo, okuhlanganisa abantu, izilwane, izitshalo, ngisho namabhaktheriya. Ukutheleleka ngama-virus kungaba nemiphumela ehlukahlukene, kuye ngegciwane kanye nesilwane esiliphethe.
Kubantu nasezilwaneni, amagciwane angabangela izifo ezahlukahlukene, kusukela ezifweni ezincane njengomkhuhlane ovamile kuya kwezimbi nezibulalayo njenge-HIV/AIDS, i-Ebola, kanye ne-COVID-19. Amanye amagciwane, njengegciwane le-herpes simplex, angabangela ukutheleleka okucashile impilo yonke okungaphindeka ngezikhathi ezithile.
Ezitshalweni, amagciwane angabangela izifo ezibhubhisayo ezitshalweni zezolimo, njenge-tobacco mosaic kanye ne-papaya ringspot. Lokhu kungabangela ukulahlekelwa okukhulu kwezomnotho.
Ama-bacteriophage, ahlasela amabhaktheriya, anemiphumela eyinkimbinkimbi. Angalawula ukwanda kwamabhaktheriya endaweni ezungezile futhi adlale indima ebalulekile ekujikelezeni kwezakhamzimba. Ngaphezu kwalokho, asetshenziswa futhi ekwelashweni kwama-phage, lapho ama-phage asetshenziswa khona ukwelapha izifo zamabhaktheriya ezingamelani nama-antibiotic.
Izinzuzo kanye nokusetshenziswa kwama-virus
Nakuba ngokuvamile kubhekwa njengosongo ngenxa yekhono lawo lokubangela izifo, amagciwane nawo anezinzuzo ezibalulekile kanye nokusetshenziswa kwesayensi nobuchwepheshe.
- Ucwaningo LwezokwelaphaAmagciwane asetshenziswa njengamathuluzi okutadisha ukusebenza kwezakhi zofuzo kanye nezindlela zesifo. Isibonelo, amagciwane asetshenziswe ukuqonda ukulawulwa kwezakhi zofuzo kanye nomjikelezo weseli, kanye nokuhlonza izinhloso ezingaba khona zokwelapha ngemithi.
- Ukwelashwa Ngezakhi Zofuzo: Amagciwane aguqulwe izakhi zofuzo asetshenziselwa ukuletha izakhi zofuzo zokwelapha kumaseli eziguli. Ukwelashwa kwezakhi zofuzo okusekelwe kumagciwane kubonise impumelelo ekwelapheni izifo ezahlukahlukene zezakhi zofuzo, okuhlanganisa i-muscular dystrophy kanye ne-hemophilia.
- Ukukhiqizwa Kwemithi YokugomaAma-virus avame ukusetshenziswa njengezibonelo zokuthuthukisa imijovo. Eminye imijovo esebenza kahle kakhulu, njengemijovo ye-polio kanye ne-hepatitis B, yasungulwa kusetshenziswa ama-virus abuthakathaka noma angasebenzi.
- I-Biotechnology kanye NezimboniAma-virus asetshenziswa futhi ezinhlotsheni ezahlukene zezimboni, okuhlanganisa nokukhiqizwa kwama-enzyme namakhemikhali. Ama-bacteriophage, isibonelo, asetshenziswa ekulawuleni izinto eziphilayo ukulawula amabhaktheriya abangela izifo embonini yokudla neyezolimo.
Izinselele Ekulawuleni Amagciwane
Nakuba kwenziwe intuthuko enkulu ocwaningweni nasekwelapheni izifo ezibangelwa amagciwane, kusenezinselelo eziningi. Inselele enkulu eyodwa ukuvela ngokushesha kwamagciwane, okungakhiqiza izinhlobo ezintsha ezithelelanayo noma ezingamelani nemijovo kanye nokwelashwa. Lesi simo sibonakala kumagciwane omkhuhlane kanye ne-SARS-CoV-2, okubangele ubhubhane lwe-COVID-19.
Ngaphezu kwalokho, i-zoonoses, ukudluliselwa kwamagciwane phakathi kwezinhlobo, ibeka engcupheni enkulu empilweni yabantu nezilwane. Ukubhekana nale nselele kudinga ukubhekwa okusebenzayo, ukuthuthukiswa kwemithi yokugoma emisha kanye nokwelashwa, kanye nezinqubomgomo zempilo yomphakathi ezifanele.
Isiphetho
Ama-virus ayizinto eziphilayo ezihlukile ezidlala indima ebalulekile ezindaweni zemvelo kanye nesayensi. Nakuba ngokuvamile aziwa njengezimbangela zezifo, ama-virus nawo anezicelo eziwusizo ocwaningweni nasebuchwephesheni. Ukuqonda okujulile ngama-virus, imijikelezo yawo yokuphila, kanye nokusebenzisana nabantu abawaphethe kuzoqhubeka nokuvula amathuba amasha okuthuthukiswa kwezindlela zokwelapha kanye nobuchwepheshe obungathuthukisa impilo yabantu kanye nokusimama kwemvelo.
