Qhov sib txawv tseem ceeb ntawm alpha thiab beta helix yog nyob ntawm hom Hydrogen bonding lawv tsim los tsim cov qauv no. Alpha helices tsim intra-molecular hydrogen bonds thaum lub beta helices tsim inter-molecular hydrogen bonds.
Cov proteins nyuaj muaj plaub lub koom haum cov txheej txheem - thawj, theem nrab, theem nrab thiab plaub. Cov txheej txheem thib ob ntawm cov proteins tsim cov peptide chains hauv kev sib txawv. Cov peptide chains muaj cov amino acid sequences khi los ntawm peptide bonds. Yog li ntawd, muaj ob lub ntsiab theem nrab hauv cov proteins li alpha helix thiab beta helix. Tsis tas li ntawd, muaj lwm cov qauv theem ob hu ua beta tig thiab hairpin lug. Feem ntau, kab lus no tsom rau qhov sib txawv ntawm alpha thiab beta helix.
Alpha Helix yog dab tsi?
Proteins muaj plaub theem ntawm lub koom haum. Ntawm cov no, alpha helix yog cov qauv thib ob ntawm cov proteins. Thiab, cov qauv no zoo li tus pas nrig uas raug mob nyob ib ncig ntawm lub hauv paus axis. Tsis tas li ntawd, alpha helix yog txoj cai helix. Txawm li cas los xij, sab laug tes helices kuj tuaj yeem muaj. Ntawm no, peptide bonds tsim los ntawm cov amino-terminal mus rau carboxy-terminal. Amino acids txuas nrog ib leeg ntawm cov peptide bonds. Intra-molecular hydrogen bonds yog qhov laj thawj tseem ceeb rau kev tsim cov alpha helix.
Daim duab 01: Alpha Helix
Kev npaj ntawm alpha helix nyob ntawm qhov hydrophilic thiab hydrophobic xwm ntawm cov protein. Yog hais tias cov amino acid sib lawv liag muaj ntau ntawm cov hydrophilic R (variable) pawg, cov R pawg taw qhia mus rau aqueous theem. Yog tias cov pab pawg sib txawv yog hydrophobic, lawv yuav tawm mus rau theem hydrophobic ntawm ib puag ncig. Hauv ob qho xwm txheej, cov pab pawg R zoo li nthuav tawm ntawm cov qauv helical. Vim yog cov yam ntxwv ntawm cov qauv no, alpha helix tiv taus ntau dua rau kev hloov pauv. Yog li, lub xub ntiag ntawm Hydrogen bonds stabilizes tus qauv ntawm alpha helix. Muaj qhov nruab nrab ntawm 3.6 residues ib zaug nyob rau hauv ib qho alpha helix raws li nws yuav siv 3.6 residues rau hydrogen bonds los tsim. Qee cov qauv proteins xws li collagen thiab keratin yog nplua nuj nyob rau hauv alpha helices.
Beta Helix yog dab tsi?
A beta helix yog qhov thib ob feem ntau cov qauv ntawm cov protein. Txawm hais tias nws tsis zoo li alpha helix, muaj beta helices tseem ua lub luag haujlwm tseem ceeb hauv cov qauv protein. Kev tsim ntawm beta helix tshwm sim los ntawm ob nplooj ntawv beta txheej txheem nyob rau hauv ib qho piv txwv los yog ib qho kev tiv thaiv kev sib txuam. Cov nplooj ntawv no mam li ua rau hauv cov qauv helical. Inter-molecular Hydrogen bonds ntawm ob daim ntawv strands pab tsim cov beta helix.
Daim duab 02: Beta Helix
Beta helices tuaj yeem yog ob sab tes xis lossis sab laug nyob ntawm lawv cov qauv khi. Thaum tsim cov beta helix, cov pab pawg sib txawv ntawm ob nplooj ntawv beta yuav npaj nyob rau hauv lub hauv paus ntawm lub helix. Yog li ntawd, feem ntau ntawm cov pab pawg tsim cov nplooj ntawv beta muaj cov haujlwm hydrophobic.
Hauv qhov sib piv rau alpha helix, 17 qhov seem tsim ib qho tig hauv Beta helices. Cov hlau ions muaj peev xwm ua kom cov tsim ntawm Beta helix. Zoo ib yam li alpha helix, Hydrogen bonds txhawb nqa cov qauv ntawm Beta helix. Carbonic anhydrase enzyme thiab pectate lyase yog ob cov proteins uas nplua nuj nyob hauv beta helices.
Dab tsi zoo sib xws ntawm Alpha thiab Beta Helix?
- Alpha thiab Beta Helix yog ob lub qauv thib ob ntawm cov proteins.
- Amino acids yog cov monomers ntawm ob qho tib si theem nrab.
- Tsis tas li ntawd, cov tshuaj lom neeg ntawm alpha thiab beta helices yog carbon, hydrogen, oxygen, nitrogen, thiab sulfur.
- Tsis tas li, ob lub tsev kawm theem nrab txhim kho mus rau hauv lub koom haum qib siab.
- Ntxiv mus, ob qho tib si tau ruaj khov los ntawm hydrogen bonds.
- Nyob rau hauv ob qho tib si qauv, lub hydrophobicity yog txiav txim los ntawm lub xub ntiag ntawm cov R pawg ntawm cov amino acids.
Qhov txawv ntawm Alpha thiab Beta Helix yog dab tsi?
Qhov sib txawv tseem ceeb ntawm alpha thiab beta helix yog hom hydrogen bonding lawv qhia. Alpha helix qhia intra-molecular hydrogen bonding thaum beta helix qhia inter-molecular hydrogen bonding. Tsis tas li ntawd, alpha helix tsim ib sab tes xis helix, thaum beta helix tuaj yeem tsim ob sab xis thiab sab laug tes. Yog li, qhov no kuj yog qhov sib txawv tseem ceeb ntawm alpha thiab beta helix.
Ntxiv mus, qhov sib txawv ntxiv ntawm alpha thiab beta helix yog tias alpha helix tsim tshwm sim los ntawm kev sib tw ntawm cov amino acid ib ntus, thaum nyob rau hauv beta helix tsim ob nplooj ntawv beta ob qho tib si los yog kev sib tw ua ke yog khi rau. tsim cov qauv helical.
Cov info-graphic hauv qab no nthuav qhia ntau ntxiv txog qhov sib txawv ntawm alpha thiab beta helix.
Summary – Alpha vs Beta Helix
Ob leeg alpha helices thiab beta helices yog qhov tseem ceeb hauv kev txheeb xyuas thiab txiav cov qauv protein ntau. Ob hom yog cov qauv thib ob ntawm cov protein. Txawm li cas los xij, alpha helix yog helical twist ntawm amino acid sequences. Nyob rau hauv sib piv, beta helix tsim tshwm sim los ntawm Hydrogen bonding ntawm parallel los yog anti-parallel beta nplooj ntawv. Tsis tas li ntawd, Hydrogen bonding yog intra-molecular hauv alpha helix daim ntawv thaum lub hydrogen bonding yog inter-molecular hauv beta helix daim ntawv. Tsis tas li ntawd, ob qho tib si cov qauv no muaj ib pawg R, uas txiav txim siab hydrophobicity ntawm cov protein. Yog li, qhov no qhia txog qhov sib txawv ntawm alpha thiab beta helix.
