Poʻomanaʻo: Nā nīnau hoʻohālike a me ke kūkākūkā ʻana o nā lula hoʻohui kumu
Pendahuluan
I loko o ka genetics, ʻo nā lula hoʻohui kumu he kumu koʻikoʻi no ka wehewehe ʻana i ke ʻano o ka hoʻokumu ʻana a me ka hana ʻana o nā kaula DNA a me RNA. I loko o ka DNA, hoʻopili pololei nā kumu nitrogenous: adenine (A) e hui pū me thymine (T), a guanine (G) e hui pū me cytosine (C). I loko o ka RNA, pani ka uracil (U) i ka thymine. He mea koʻikoʻi kēia mau lula no ka hana hou ʻana o ka DNA a me ka hoʻopili ʻana o ka RNA.
E hōʻike ana kēia ʻatikala i kekahi mau pilikia hoʻohālike e pili ana i nā lula hoʻohui kumu, me kā lākou mau kūkākūkā ʻana. Manaʻolana ʻia e kōkua kēia i ka poʻe heluhelu e hoʻomaopopo i nā manaʻo kumu a me kā lākou noi ʻana i nā ʻano pōʻaiapili olaola like ʻole.
Nā Nīnau Laʻana a me ke Kūkākūkā
1. Nīnau 1: Ke helu ʻana i ka helu o nā kumu i loko o ka DNA
Eia kekahi laʻana, aia i loko o kahi kaula DNA he 30% guanine. E helu i ka pakeneka o nā kumu cytosine, adenine, a me thymine i loko o ke kaula.
Kūkākūkā:
Wahi a nā lula o ka hoʻohui kumu, hui mau ka guanine (G) me ka cytosine (C). Inā he 30% ka guanine, a laila pono pū ka cytosine he 30%. ʻOiai ʻo ka pakeneka holoʻokoʻa o nā kumu āpau he 100%, hiki iā mākou ke helu i ka pakeneka o ka adenine (A) a me ka thymine (T) me ka hoʻohana ʻana i ke ʻano:
\[
\text{Pakeneka A} + \text{Pakeneka T} + \text{Pakeneka G} + \text{Pakeneka C} = 100\%
\]
Ma ke kau ʻana i nā waiwai o G a me C, loaʻa iā mākou:
\[
\text{Pakeneka A} + \text{Pakeneka T} + 30\% + 30\% = 100\%
\]
\[
\text{Pakeneka A} + \text{Pakeneka T} = 40\%
\]
No ka mea ua hui pū ʻia ʻo A me T, a laila:
\[
\text{Pakeneka A} = \text{Pakeneka T} = 20\%
\]
No laila, ʻo ka pakeneka o kēlā me kēia kumu he G = 30%, C = 30%, A = 20%, a me T = 20%.
2. Nīnau 2: Ke hana ʻana i kahi kaulahao pālua DNA
Hāʻawi ʻia ke kaʻina kumu ma kekahi kaula DNA ʻo 5′-ATCGGATCGA-3′. E hoʻoholo i ke kaʻina kumu ma kekahi kaula.
Kūkākūkā:
Ma ka hoʻohana ʻana i nā lula hoʻohui kumu, ʻike mākou e hui pū ana ʻo A me T, ʻo T me A, ʻo C me G, a me G me C. Ma ka hahai ʻana i kēia mau lula, hiki iā mākou ke hoʻoholo i ke kaʻina o nā kumu ma ke kaula i hui pū ʻia:
– Nā hui ʻo A me T
– Ua hui pū ʻia ʻo T me A
– Ua hui pū ʻia ʻo C me G
– Ua hui pū ʻia ʻo G me C
– Ua hui pū ʻia ʻo G me C
– Nā hui ʻo A me T
– Ua hui pū ʻia ʻo T me A
– Ua hui pū ʻia ʻo C me G
– Ua hui pū ʻia ʻo G me C
– Nā hui ʻo A me T
No laila, ʻo ke kaʻina kumu i loko o ke kaulahao i hui pū ʻia ʻo 3′-TAGCCTAGCT-5′.
3. Nīnau 3: Ka hoʻololi ʻana o ka DNA i loko o ka RNA
Hāʻawi ʻia ke kaʻina kumu DNA ma lalo nei: 5′-GATTACA-3′. E hoʻoholo i ke kaʻina kumu i loko o ka RNA i kākau ʻia.
Kūkākūkā:
I ke kaʻina hana o ka transcription, hoʻohana ʻia ke kaʻina kumu i loko o ka DNA ma ke ʻano he template no ka hana ʻana i ka RNA. I loko o ka RNA, pani ka uracil (U) i ka thymine (T). A laila hoʻokumu ʻia ke kaʻina kumu RNA hopena ma ka pani ʻana i kēlā me kēia kumu me kona kumu like (koe wale nō ʻo T, ka mea i lilo iā U):
– Lilo ʻo G i C
– Lilo ʻo A i U
– Lilo ʻo T i A
– Lilo ʻo T i A
– Lilo ʻo A i U
– Lilo ʻo C i G
– Lilo ʻo A i U
No laila, ʻo ke kaʻina kumu i loko o ka RNA ʻo 5'-CUAAUGU-3'.
4. Nīnau 4: Ke ʻIke ʻana i nā Mutations i loko o ka DNA
Ua ʻike kekahi ʻepekema ua loli kekahi kumu i loko o ka moʻo DNA 5′-TACGGCAT-3′, e pani ana i ka lua o ke kumu me kekahi kumu ʻē aʻe. Ma muli o kēia ʻikepili, he aha ka hopena o kēia loli ʻana i ka protein i loaʻa?
Kūkākūkā:
Ma kēia kūlana, pono mākou e hoʻoholo mua i nā hui kumu maʻamau a me ke ʻano o ka moʻo RNA:
Kaʻina DNA maʻamau: 5′-TACGGCAT-3′
ʻO ka mutant manaʻo: 5′-TTCGGCAT-3′ (ua pani ʻia ka lua o ka T e kekahi kumu ʻē aʻe)
Pālua maʻamau: 3′-ATGCCGTA-5′
Pālua Mutant: 3′-AAGCCGTA-5′
RNA maʻamau: 5′-AUGCCGUA-3′
RNA Mutant: 5′-AAGCCGUA-3′
Ma muli o ka papa codon, e loli ke kaʻina maʻamau AUG (methionine) i AAG (lysine). ʻO ka hoʻololi ʻana o kahi waikawa amino hoʻokahi i loko o ke kaulahao hiki ke hoʻopilikia i ka hana o ka protein hopena, ma muli o ke kūlana a me nā waiwai kemika o ka waikawa amino i pili.
5. Nīnau 5: Ke helu ʻana i ka hopena o ka DNA Denaturation
Ke hoʻololi ʻia ke ʻano o ka DNA, ua haki nā pilina ma waena o nā kumu naikokene. Ma kēia hoʻokolohua, ua ʻike mākou aia kahi moʻo DNA kikoʻī he 60% GC-pairing. Inā hoʻonui ʻia ka mahana, pehea lā e hoʻohālikelike ʻia ai ke kūpaʻa o kēia DNA me ka DNA nona ka 40% GC-pairing?
Kūkākūkā:
Ua hoʻopili ʻia nā hui kumu GC e ʻekolu mau pilina hydrogen, ʻoiai ua hoʻopili ʻia nā hui kumu AT e ʻelua mau pilina hydrogen. No laila, ʻoi aku ka paʻa o nā moʻo DNA me ka pakeneka GC kiʻekiʻe a koi aku i nā mahana kiʻekiʻe e hoʻololi i ke ʻano.
Ma kēia hihia, ʻoi aku ka paʻa o ka DNA me nā hui GC 60% a ʻoi aku ka kūpaʻa i ka piʻi ʻana o ka mahana ma mua o ka DNA me nā hui GC 40% wale nō, no ka mea, ʻoi aku ka nui o ka ikehu e pono ai e uhaʻi i nā pilina hydrogen e hoʻopili ana i nā hui GC.
Ka hopena
ʻO ka hoʻomaopopo ʻana i nā lula o ka hoʻohui kumu he mea nui ia i ka biology molecular, ʻoi aku hoʻi i loko o ke ʻano o ka hana hou ʻana o ka DNA, ka transcription, a me ka mutation. Hōʻike nā hiʻohiʻona ma luna i nā noi kūpono a me nā hopena o kēia mau lula i ke aʻo ʻana i ka genetics a me ka biotechnology. ʻO ka hohonu o ko mākou hoʻomaopopo ʻana i kēia mau kaʻina hana, ʻo ka nui o kā mākou hoʻolaha ʻana i kā mākou mau hana i ka noiʻi genetic a me ko mākou hoʻomaopopo ʻana i ke ola ma ka pae molecular.
