Iyini igciwane? Kuyini?

Abamele bendawo yegciwane bangamaqembu akhethekile amafomu okuphila. Abanayo nje isakhiwo esikhethekile kuphela, kodwa futhi kubhekene nokusetshenziswa komzimba okuqondile. Kulesi sihloko, sizofunda uhlobo lokuphila olungelona lweselula - igciwane. Lokho okuhlanganiswayo, ukuthi landa kanjani nokuthi lidlala indima emvelweni, uzofunda ngokulifunda.

Ukutholakala kwamafomu okungewona amaselula okuphila

Usosayensi waseRashiya u-D. Ivanovsky ngo-1892 wafunda i-agent yokukhathaza yesifo sogwayi - umdwebo wezokwelapha. Uthole ukuthi i-agent ye-pathogenic ayilona ibhaktheriya, kodwa ifomu elikhethekile, kamuva elibizwa ngokuthi igciwane. Ekupheleni kwekhulu le-19, ama-microscopes aphezulu awazange asetshenziswe ku-biology, ngakho-ke usosayensi wayengazi ukuthi yiziphi i-molecule igciwane, futhi ukulibona nokulichaza. Emva kokudalwa kwe-microscope ye-electron ekuqaleni kwekhulu lama-20, umhlaba wabona abameli bokuqala bombuso omusha, obengobangela wengozi eziningi futhi ezinzima ukuphatha izifo zomuntu, kanye nezinye izinto eziphilayo: izilwane, izitshalo, amabhaktheriya.

Isimo samafomu okungewona amaselula ohlelweni lwezinto eziphilayo

Njengoba kushiwo ngaphambili, lezi ziphilayo zihlangene endaweni yesihlanu yokuphila - amagciwane. Isici esiyinhloko se-morphological, isici sabo bonke amagciwane, ukungabikho kwesakhiwo samaselula. Kuze kube manje, umhlaba wesayense awuyekanga izingxoxo ukuthi ngabe amafomu angewona amaselula ayizinto eziphilayo ngokugcwele kwegama. Phela, zonke izibonakaliso ze-metabolism kuzo zingenzeka kuphela emva kokungena esitokisini esiphilayo. Kuze kube yilokhu, ama-virus aziphatha njengezinto zenyama engapheli: abanayo ukuphendula okuyisimangaliso, azikhiqizi. Ekuqaleni kwekhulu lama-20, kwavela imibuzo eminingi ngaphambi kososayensi: iyini igciwane, igobolondo lalo liyilo, yini engaphakathi kwe-particle virus? Izimpendulo zamukelwe ngenxa yeminyaka eminingi yokucwaninga nokuhlolwa, okwakungumsisekelo wesiyalo esisha sesayensi. Kwavela ekuhlanganiseni kwezinto eziphilayo kanye nemithi futhi kuthiwa i-virology.

Izici zesakhiwo

Inkulumo ethi "yonke elula ehlakaniphile" ngokuqondile ihlobanisa namafomu okungewona amaselula okuphila. Igciwane liqukethe ama-molecule we-nucleic acid - i-DNA noma i-RNA, eboshwe igobolondo yamaprotheni. Akanayo amandla akhe namaparatheni okuhlanganisa amaprotheni. Ngaphandle kweli cell, i-virus ayinayo uphawu lwezinto eziphilayo: akukho ukuphefumula, noma ukukhula, noma ukucasula, noma ukukhiqiza. Kuzo zonke lezi zivele, kukhona okukodwa okudingekayo: ukuthola isisulu - iseli ephilayo, ukuqondisa isisindo salo sogesi ku-nucleic acid bese ekugcineni siyichithe. Njengoba sekushiwo ngaphambili, imvilophu yegciwane iqukethe ama-molecule amaphrotheni anesakhiwo esihlelekile (amagciwane alula).

Uma ukwakhiwa kwemvilophu kufaka phakathi izingqungquthela ze-lipoprotein, okuyiyona ingxenye yechungechunge le-cytoplasmic yesitokisi esithintekayo, lawo magciwane abizwa ngokuthi ayingxube (ama-pathogens of bexpox ne-hepatitis B). Ngokuvamile, ukubunjwa kwemvilophu yemvelo yegciwane kuhlanganisa ama-glycoprotein. Benza umsebenzi we-alamu. Ngakho-ke, njengegobolondo, futhi igciwane ngokwayo liqukethe ama-molecule wezinto eziphilayo - amaprotheni kanye ne-nucleic acid (i-DNA noma i-RNA).

Indlela amagciwane angena ngayo amangqamuzana aphilayo

Ngaphambili sasizicabangela izici zesakhiwo segobolondo ye-intracellular parasite. Igciwane liqukethe ama-molecule wezinto eziphilayo neziphilayo, futhi isakhiwo saso sineziprotheyini ezikhethekile ezibona i-plasmalemma yeseli ephilayo. Ngakho-ke, amafomu angewona amaselula anithinta izinhlobo ezithile zeseli zezinhlobo ezithile zezinto eziphilayo eziphilayo. Isibonelo, ama-virus wezinja zenhlanzi awasongela impilo yabantu. Ngaphakathi kwamaseli, i-parasite ihamba ngezindlela eziningana:

1. Ukuhlanganisa igobolondo layo ne-membrane yeseli (i-influenza virus).
2. Nge-pinocytosis (i-agent ye-poliomyelitis yezilwane).
3. Ngomonakalo odongeni lweseli (ama-plant virus).

Ukusabalalisa kwamagciwane

Uma i-parasite ingene esitokisini, ama-molecule we-nucleic acid yayo, efakwe engxenyeni ye-nucleus genome, ithumela ulwazi mayelana nesakhiwo sezinhlayiyana zeprotheyini futhi iqala inqubo ye-biosynthesis yamaprotheni abo. Kulokhu, ama-ribosomes, ama-molecule we-ATP, i-t-RNA yamaseli esithintekayo asetshenzisiwe. Ngokufana neseli elithathelwanayo, kukhona ukunciphisa ulwazi oluthile. Khumbula ukuthi kusuka kwamaprotheni ne-nucleic acid kukhona amagciwane, okuthiwa alula. Izinhlayiya zazo ziqukethe i-RNA, ebopha ngokushesha kumagundane e-ribosomes esitokisini esithintekayo futhi ivuselele i-biosynthesis yama-molecule we-proteine yegciwane.

Umphumela wokuhlaselwa kwe-pathogen esitokisini iba yi-DNA noma i-RNA yegciwane nama-protein awo ayizinhlayiyana. Ngakho-ke, igciwane elisha esakhiwe linamakhemikhali e-nucleic acid ahlanganiswe nezinhlayiya zamaprotheni. I-membrane yesitokisi esiphezulu ibhujiswa, iseli lifa, futhi amagciwane avela kuwo angena amangqamuzana anempilo omzimba.

I-phenomenon yokuphindaphinda kabusha

Ekuqaleni kokucwaninga kwabamele balo mbuso, kwakucatshangwa ukuthi amagciwane ahlanganisa amangqamuzana, kodwa kakade u-D. Ivanovsky wazama ukuhlola ukuthi izifo eziphilayo azikwazi ukuhlukaniswa ngosizo lwezihlungi ze-microbiological: ama-pathogens adlulisa ama-pores futhi avele ku-filtrate egcina izakhiwo ezinamandla.

Ucwaningo oluqhubekayo lwasungula ukuthi igciwane liqukethe ama-molecule wezindaba eziphilayo futhi libonisa izimpawu zokuphila kuphela emva kokungena kwayo ngokuqondile esitokisini. Kulo, liqala ukwanda. Ama-virus amaningi a-RNA azalana njengoba kuchaziwe ngenhla, kodwa amanye awo, isibonelo, igciwane lesandulela ngculaza, elise-nucleus leli cell cell lidala i-DNA synthesis. Lesi simo sisho ukuphindaphinda okuphindaphindiwe. Khona-ke i-i-RNA yegciwane ihlanganiswa ekomlekheni le-DNA , futhi umhlangano wezingqimba zamaphrotheni ezinamaprotheni ezenza imvilophu yayo iqala kuwo.

Izici ze-bacteriophages

Iyini i-bacteriophage-cell noma igciwane? Iyini ifomu elingelona iselula lempilo elibandakanya? Izimpendulo zale mibuzo yilezi: yi-virus echaphazela kuphela izinto eziphilayo ze-prokaryotic - amabhaktheriya. Isakhiwo salo siyisimangaliso. Igciwane liqukethe ama-molecule wezinto eziphilayo futhi lihlukaniswe izingxenye ezintathu: ikhanda, isiqu (isembozo), kanye nezinsila zomsila. Ngaphambili - ikhanda - i-molecule ye-DNA. Okulandelayo isembozo esinomgogodla ongaphakathi ngaphakathi. Imicu yomsila ehlanganiswe nayo iqinisekisa ukuxhumeka kwegciwane kumlandi we-receptor we- plasma membrane ye- bacterium. Isimiso sesenzo se-bacteriophage sifana nesirinji. Ngemuva kokuchotshozwa kwamaprotheni ama-coat, i-molecule ye-DNA ingena emgodini ongenalutho bese ijova ibe yi-cytoplasm yeli cell target. Manje ibhaktheriya enegciwane izokwenziwa i-DNA yegciwane kanye namaprotheni alo, okungenakuphikelela ekuholela ekufeni kwayo.

Indlela umzimba ozivikela ngayo ezifweni ezibangelwa amagciwane

Imvelo idale amadivaysi okuzivikela akhethekile avimbela izifo ezibangelwa amagciwane ezitshalo, izilwane nabantu. Ama-pathogens ngokwabo aqondwa ngamaseli awo njenge-antigens. Ephendula ukutholakala kwamagciwane, umzimba uveza ama-immunoglobulins - amasosha omzimba avikelayo. Izitho zamasosha omzimba - i-thymus, i-lymph nodes - isabela ekusungulweni kwegciwane futhi ifaka iqhaza ekuthuthukiseni amaprotheni avikelayo - ama-interferon. Lezi zinto zivimbela ukuthuthukiswa kwezinhlayiya ezibandayo futhi zivimbela ukukhiqizwa kwazo. Zombili izinhlobo zokuphendula okuvikelayo, okucatshangwe ngenhla, zibhekisela ekuzivikelweni komzimba. Enye indlela yokuvikelwa kuyiselula. Ama-leukocytes, ama-macrophages, ama-neutrophils athatha izinhlayiya zegciwane bese ewaphula.

Ukubaluleka kwamagciwane

Akuyona imfihlo ukuthi iningi libi. Lezi zinambuzane ezincane ezincane (15 kuya ku-450 nm), ezibonakalayo kuphela kwi-microscope ye-electron, zibangela lonke izifo eziyingozi neziphazamisayo zazo zonke izinto ezikhona emhlabeni, ngaphandle kokunye. Ngakho-ke, kubantu, ama-virus anithinta izitho ezibalulekile nezinhlelo, isibonelo, ukwesaba (i-rabies, encephalitis, poliomyelitis) nge-immune (i-AIDS), ukugaya (isifo sofuba), ukuphefumula (umkhuhlane, ama-adenoinfections). Izilwane zinegciwane lesilwane, isifo, nezitshalo - nge-necroses ehlukahlukene, ama-patches, ama-mosaic.

Ukuhlukahluka kwabamele umbuso akukaqondwa ngokugcwele. Ubufakazi ukuthi kuze kube manje bathola izinhlobo ezintsha zegciwane futhi baxilonga ngaphambili okwenzekanga izifo. Isibonelo, phakathi nekhulu le-20, igciwane leZika litholakala e-Afrika. Itholakala emzimbeni wemiyane, lapho, lapho ilunywa, ihlasela abantu nezinye izilwane ezincelisayo. Izimpawu zalesi sifo zibonisa ukuthi i-pathogen ithinta ngokuyinhloko isimiso sezinzwa ezisemkhatsini futhi kubangele i-microcephaly ezinsana ezisanda kuzalwa. Abantu abathwala leli gciwane kufanele bakhumbule ukuthi bafaka ingozi engozini kubalingani babo, ngoba ezimweni zokwelapha zokudluliswa ngokocansi kwalesi sifo zibhaliswe.

Indima enhle yamagciwane ingabonakala ekusetshenzisweni kwabo ekulwa nezinambuzane ezibulala izinambuzane, kwezobuchwepheshe bokufuyelwa kwezakhi zofuzo.

Kuleli phepha, sichaze ukuthi yiliphi igciwane, ukuthi i-particle yayo iqukethe, ukuthi izilwane zizivikela kanjani kuma-pathogenic agents. Sithole futhi indima ukuthi amafomu okungewona amaselula okuphila adlala emvelweni.