Ngā Tauira Pātai mō te DNA me ngā Ira
Pendahuluan
I roto i te koiora ngota, ko te DNA (Deoxyribonucleic Acid) me ngā ira he ariā matua e whakamārama ana i te tukunga iho o ngā āhuatanga me te mahi a ngā mea ora. Ko te DNA he ngota e penapena ana i ngā mōhiohio ira katoa e tika ana hei whakahaere i te hanganga me te mahi a te mea ora. Ko ngā ira, i tētahi atu ringa, he wāhanga o te DNA e waehere ana mō ngā pūmua motuhake, RNA rānei. He mea nui te mārama ki te DNA me ngā ira mō te hunga e hiahia ana ki te koiora, te hangarau koiora, te rongoā, me ngā mara e pā ana. Ka matapakihia e tēnei tuhinga ētahi pātai e pā ana ki ēnei kaupapa, me ō rātou whakamārama.
1. Pātai 1: Hanganga DNA
Pātai: Whakamāramahia te hanganga takirua o te DNA, me te whakaingoa i ngā wāhanga matua e hanga ana i taua hanganga.
Kōrero: He porowhita takirua te DNA, arā, he miro e rua e takai ana tetahi ki tetahi, he rite tonu ki te arawhata porowhita. I tuatahitia tēnei hanganga e James Watson rāua ko Francis Crick i te tau 1953, i toa hoki rāua i te Tohu Nobel mō tā rāua kitenga. E toru ngā wāhanga matua o te DNA: te phosphate, te huka deoxyribose, me ngā turanga hauota. Ko ēnei turanga hauota ko te adenine (A), te thymine (T), te cytosine (C), me te guanine (G). I roto i te porowhita takirua, ka honoa ēnei turanga: Ko te A e hono ana ki a T mā roto i ngā hononga hauwai e rua, ā, ko te C e hono ana ki a G mā roto i ngā hononga hauwai e toru. Ko ngā aho o te arawhata DNA e tohuhia ana e te huka me te phosphate, ko ngā taumata e tohuhia ana e ngā takirua turanga.
2. Pātai 2: Te Whakatakotoranga DNA
Pātai: He aha te tikanga o te tāruaruatanga DNA ā-haurua-pūmau, ā, he aha i hiranga ai?
Kōrero: Ko te tāruarua DNA ā-haurua-aroturuki he tukanga e titoa ana i ia ngota DNA hou he aho taketake kotahi me te aho hou kotahi. Ina tāruarua te DNA, ka wetekina te porowhita takirua pērā i te reti, ā, ka mahi ia aho taketake hei tauira mō te hanganga o tētahi aho hou. He mea nui tēnei tukanga nā te mea ka whakarite kia whiwhi ia pūtau tamahine i tētahi aho DNA kotahi e ōrite ana ki te aho taketake, kia mau tonu ai te pono o ngā mōhiohio ira puta noa i ngā whakatupuranga. Ka āwhina te tāruarua ā-haurua-aroturuki ki te whakaiti i ngā hapa i te wā o te wehenga pūtau, ā, he mea nui hoki mō te tukunga ira tika.
3. Pātai 3: Te Whakapuakitanga Ira
Pātai: Me pēhea te puta o ngā tukanga whakawhiti me te whakamāori i roto i te whakaaturanga ira?
Kōrero: E rua ngā wāhanga matua o te whakaaturanga ira: te tuhi me te whakamāori. I roto i te tuhi, ka whakamahia he wāhanga o te DNA kei roto he ira motuhake hei tauira hei hanga i te RNA karere (mRNA). Ka puta tēnei tukanga i roto i te karihi pūtau, ā, ka uru te whākōkī RNA polymerase, e herea ana ki te DNA me te hanga mRNA i runga i te raupapatanga turanga DNA. I muri i te tuhi, ka wehe te mRNA i te karihi ka haere ki ngā ribosome i roto i te cytoplasm, te wāhi e puta ai te whakamāori.
I te wā whakamāoritanga, ka pānuihia e ngā ribosome te raupapatanga turanga mRNA i roto i ngā rōpū e toru e kiia nei ko ngā codon. He motuhake ia codon mō tētahi waikawa amino motuhake. Ka haria e te RNA whakawhiti (tRNA) ngā waikawa amino e rite ana ki te ribosome, kātahi ka huihuia hei mekameka polypeptide i runga i te raupapatanga codon. Kia oti te mekameka polypeptide, ka tukatukahia anō kia noho hei pūmua mahi e whai wāhi nui ana ki roto i te pūtau.
4. Pātai 4: Te Hurihanga Ira
Pātai: He aha te tikanga o te whakarerekētanga ira, ā, he aha te pānga o ngā whakarerekētanga ira ki ngā rauropi?
Kōrero: Ko ngā whakarerekētanga ira he huringa i roto i te raupapatanga turanga o te DNA. Ka puta noa ēnei huringa i te wā e whakaputarua ana te DNA, ka puta rānei i ngā āhuatanga o waho pērā i te irahiko me ngā matū whakarerekētanga ira. Ka pāngia ngā rauropi e ngā whakarerekētanga ira i ngā huarahi maha, i runga i te momo me te wāhi o te huringa.
Ka taea te whakarōpū i ngā whakarerekētanga ki ngā momo matua e toru:
– Ngā whakarerekētanga ira: kei roto ko ngā huringa i roto i te niukariota kotahi. Ka puta pea ēnei i roto i te ahua o ngā whakakapinga (te whakakapi i tētahi pūtake ki tētahi atu), ngā whakaurunga, ngā mukunga rānei.
– Te whakarerekētanga ira tangata: ka hua ake te whakakapinga o tētahi waikawa amino i roto i te pūmua.
– Ngā whakarerekētanga ira koretake: ka hangaia ngā kōtona aukati wawe, ka aukati wawe i te hanganga pūmua.
– Ngā whakarerekētanga anga: nā ngā whakaurunga, ngā mukunga rānei e neke ana i te anga pānui mRNA.
Ka rerekē pea te pānga o ngā whakarerekētanga ira. Kāore he pānga o ētahi whakarerekētanga ira (ngā whakarerekētanga wahangu), ko ētahi ka whakararuraru i te mahi a te pūmua, ka puta he mate ira, i ētahi wā onge rānei, ka whakarato i tētahi painga whanaketanga.
5. Pātai 5: Te Whakamahinga o te Hangarau Koiora me te DNA Whakahou
Pātai: Whakamāramahia me pēhea te whakamahi i te hangarau DNA hangarua hei whakawhanake i ngā hua ātete ki ngā pepeke.
Kōrero: Ko te hangarau DNA recombinant e uru ana ki te whakakotahi i ngā ira mai i ngā rauropi rerekē hei whakaputa i ngā rauropi me ngā āhuatanga hou e hiahiatia ana. I roto i te whanaketanga o ngā hua ātete-pest, ka taea te tango i ngā ira e whakamārama ana i ngā pūmua e patu ana i ngā pepeke, e aukati ana rānei i tō rātou whanaketanga mai i ngā huakita ka whakaurua ki roto i te ira tipu.
Hei tauira, ko te Bacillus thuringiensis (Bt) he huakita e whakaputa ana i tētahi pūmua he paitini ki ētahi pepeke. Ka taea te wehe i te ira e whakamārama ana i te pūmua Bt me te whakauru ki roto i te DNA tipu mā te whakamahi i te hangarau DNA recombinant. Ko te hua Bt ka puta mai ka whakaputa i tana ake pūmua, ā, ka taea te tiaki i a ia anō mai i ngā whakaekenga pepeke me te kore e hiahiatia he patupatu matū tāpiri. Ehara i te mea ka whakanui ake i te hua o te hua anake engari ka whakaitihia hoki te pānga taiao o te whakamahinga patupatu.
Te Katinga
Ehara i te mea he mea nui te mārama ki te DNA me ngā ira mō te hunga e mahi ana i roto i te koiora me te rongoā anake, engari mō te marea whānui hoki, i runga i tōna hiranga ki te hangarau koiora me ō tātou oranga o ia rā. Mā te tūhura i ngā tauira raruraru me ngā kōrero, ko te tumanako ka hōhonu ake te māramatanga ki tēnei kaupapa nui. Ngā mihi ki a koutou mō te whai mai, ā, ko te tumanako kua whai hua tēnei.
