Amino acids, cov qauv uas tau tham hauv chav kawm chemistry high school, yog cov khoom tseem ceeb rau tib neeg lub cev. Proteins, uas muaj cov amino acid residues, yog tsim nyog rau ib tug neeg ua hauj lwm tag nrho.
Definition
Amino acids, cov qauv uas yuav tau tham hauv qab no, yog cov organic tebchaw uas nws cov molecules muaj cov amino thiab carboxyl pawg. Carboxyl muaj cov carbonyl thiab hydroxyl pawg.
Koj tuaj yeem xav txog cov amino acids ua cov khoom siv ntawm carboxylic acids, qhov twg hydrogen atom hloov los ntawm ib pawg amino.
Txhim kho cov khoom siv tshuaj lom neeg
Amino acids, uas nws cov qauv dav dav tuaj yeem sawv cev ua CnH2nNH2COOH, yog amphoteric tshuaj compounds.
Lub xub ntiag ntawm ob pawg ua haujlwm hauv lawv cov molecules piav qhia txog qhov ua tau ntawm cov organic tshuaj uas nthuav tawm cov yam ntxwv thiab cov kua qaub.
Lawv cov tshuaj aqueous muaj cov khoom ntawm cov kev daws teeb meem. Zwitterion yog ib qho amino acid molecule qhov twg cov amino pawg yog NH3 + thiab carboxyl yog -COO-. Ib qho molecule ntawm hom no muaj lub sijhawm tseem ceeb dipole, thaumtus nqi tag nrho yog xoom. Crystals ntawm ntau cov amino acids yog tsim los ntawm cov molecules.
Ntawm cov khoom tseem ceeb tshaj plaws ntawm cov khoom hauv chav kawm no, cov txheej txheem polycondensation tuaj yeem paub qhov txawv, vim tias cov polyamides tau tsim, suav nrog cov proteins, peptides, nylon.
Amino acids, cov qauv dav dav uas yog CnH2nNH2COOH, hnov mob nrog cov kua qaub, hauv paus, hlau oxides, ntsev ntawm cov kua qaub tsis muaj zog. Cov kev txaus siab tshwj xeeb yog kev sib cuam tshuam ntawm cov amino acids nrog cawv muaj feem xyuam rau esterification.
Txoj kev ntawm isomerism
txhawm rau sau cov qauv qauv ntawm cov amino acids, peb nco ntsoov tias ntau cov amino acids koom nrog hauv kev hloov pauv biochemical muaj ib pawg amino hauv ib txoj hauj lwm los ntawm pawg carboxyl. Xws li cov pa roj carbon atom yog qhov chaw chiral, thiab cov amino acids raug suav tias yog optical isomers.
Cov qauv qauv ntawm cov amino acids muab lub tswv yim ntawm qhov chaw ntawm cov pab pawg ua haujlwm tseem ceeb uas tsim cov khoom siv, txheeb ze rau cov pa roj carbon activated.
Natural amino acids uas yog ib feem ntawm cov protein molecules yog cov neeg sawv cev ntawm L-series.
Kho qhov muag isomers ntawm amino acids yog tus cwj pwm los ntawm kev qeeb qeeb uas tsis yog-enzymatic racemization.
Txoj kev ntawm ib-compound
Ib qho qauv ntawm cov tshuaj ntawm hom no suav tias qhov chaw ntawm cov amino pawg ntawm cov pa roj carbon thib ob. 20 amino acids, cov qauv uas tau txiav txim siab txawm nyob hauv chav kawm biology hauv tsev kawm, kuj yogbelongs rau hom no. Piv txwv li, cov no muaj xws li alanine, asparagine, serine, leucine, tyrosine, phenylalanine, valine. Nws yog cov tebchaw uas ua rau tib neeg caj ces code. Ntxiv rau cov qauv kev sib txuas? Tsis yog-tus qauv amino acids, uas yog lawv cov derivatives, kuj pom muaj nyob rau hauv cov protein molecules.
Kev faib tawm los ntawm kev sib txuas
Yuav ua li cas cov amino acids tseem ceeb sib cais? Cov qauv ntawm cov chav kawm no yog subdivided raws li lub hauv paus physiological rau hauv ib nrab hloov, muaj peev xwm ua ke hauv tib neeg lub cev. Ordinary compounds synthesized in any living organism is also cais.
Kev faib rau pawg radical thiab kev ua haujlwm
Cov qauv amino acid txawv ntawm cov qauv ntawm cov radical (sab pawg). Muaj kev faib ua cov tsis-polar molecules uas muaj cov hydrophobic non-polar radical, nrog rau hauv pawg polar charged. Aromatic amino acids raug suav hais tias yog ib pawg cais hauv biochemistry: histidine, tryptophan, tyrosine. Nyob ntawm cov pab pawg ua haujlwm, ntau pab pawg tau txawv. Aliphatic compounds yog sawv cev los ntawm:
- monoaminomonocarboxylic compounds, uas tuaj yeem suav tias yog glycine, valine, alanine, leucine;
- oxymonocaminocarboxylic tshuaj: threonine, serine;
- monoaminocarboxylic: glutamic, aspartic acid;
- muaj cov tshuaj sulfur: methionine, cysteine;
- diaminomonocarboxylic tshuaj: lysine, histidine, arginine;
- heterocyclic: proline, histidine,tryptophan/
Txhua yam amino acid formula tuaj yeem sau rau hauv cov ntsiab lus dav dav, tsuas yog pawg radical yuav txawv.
Qualitative definition
txhawm rau txhawm rau txheeb xyuas qhov me me ntawm cov amino acids, cov tshuaj ninhydrin tau ua tiav. Nyob rau hauv cov txheej txheem ntawm cua sov cov amino acids nrog ntau tshaj ntawm ninhydrin, ib qho khoom qab zib tau txais yog tias cov kua qaub muaj ib pawg dawb-amino, thiab cov khoom daj yog qhov zoo rau ib pab pawg tiv thaiv. Txoj kev no muaj qhov rhiab heev thiab yog siv rau colorimetric kuaj pom cov amino acids. Ntawm nws lub hauv paus, txoj kev faib chromatography ntawm daim ntawv, qhia los ntawm Martin hauv 1944, tau tsim.
Tib cov tshuaj tiv thaiv yog siv nyob rau hauv qhov tsis siv neeg amino acid analyzer. Cov cuab yeej tsim los ntawm Moore, Shpakman, Stein, yog raws li kev sib cais ntawm cov amino acid sib tov nyob rau hauv txhua kab uas muaj ion-pauv resins. Los ntawm kem, cov eluent tam sim no nkag mus rau hauv lub tov khoom, ninhydrin kuj mus ntawm no.
Cov ntsiab lus ntau ntawm cov amino acids yog txiav txim los ntawm kev siv ntawm cov xim tshwm sim. Cov kev nyeem ntawv yog kaw los ntawm photoelectric colorimeter, kaw los ntawm lub recorder.
Tsev txheej txheem zoo ib yam tam sim no siv rau hauv kev kho mob rau ntshav, cerebrospinal kua thiab kuaj zis. Nws tso cai rau koj los muab cov duab tiav ntawm cov khoom muaj txiaj ntsig zoo ntawm cov amino acids uas muaj nyob hauv cov kua roj ntsha, txhawm rau txheeb xyuas cov khoom tsis muaj nitrogen-muaj nyob hauv lawv.
Nyob ntawm nomenclature
Yuav ua li cas kom lub npe kom raugamino acids? Cov qauv thiab cov npe ntawm cov tebchaw no tau muab raws li International IUPAC nomenclature. Txoj hauj lwm ntawm pawg amino yog ntxiv rau cov carboxylic acid sib xws, pib los ntawm hydrocarbon ntawm pawg carboxyl.
Piv txwv li, 2-aminoethanoic acid. Ntxiv nrog rau lub npe thoob ntiaj teb nomenclature, muaj cov npe tsis tseem ceeb siv hauv biochemistry. Yog li, aminoacetic acid yog glycine siv nyob rau hauv cov tshuaj niaj hnub.
Yog tias muaj ob pawg carboxyl nyob rau hauv cov molecule, lub ntsiab lus -dionic ntxiv rau lub npe. Piv txwv li, 2-aminobutanedioic acid.
Rau txhua tus neeg sawv cev ntawm chav kawm no, cov qauv isomerism yog yam ntxwv, vim muaj kev hloov pauv ntawm cov qauv ntawm cov saw hlau, nrog rau qhov chaw ntawm carboxyl thiab amino pawg. Ntxiv rau glycine (tus neeg sawv cev yooj yim tshaj plaws ntawm chav kawm ntawm cov organic uas muaj oxygen)? cov khoom sib txuas ntxiv muaj daim iav antipodes (optical isomers).
Daim ntawv thov
Amino acids muaj nyob rau hauv cov xwm txheej, lawv yog lub hauv paus rau kev tsim tsiaj thiab zaub proteins. Cov tshuaj no yog siv nyob rau hauv cov tshuaj nyob rau hauv cov ntaub ntawv ntawm kev qaug zog ntawm lub cev, piv txwv li, tom qab complex phais ua hauj lwm. Glutamic acid pab tua kab mob paj hlwb, thiab histidine yog siv los kho mob plab. Hauv kev sib xyaw ntawm cov hluavtaws fibers (capron, enanth), aminocaproic thiab aminoenanthic acids ua cov khoom siv raw.
Zoo kawg
Amino acids yog cov organic tebchaw uas nyob hauv lawvmuaj ob pab pawg ua haujlwm. Nws yog cov qauv nta uas piav qhia txog qhov sib npaug ntawm lawv cov khoom siv tshuaj, nrog rau qhov tshwj xeeb ntawm lawv siv. Raws li cov txiaj ntsig ntawm kev tshawb fawb thwmsim, nws muaj peev xwm tsim tau tias cov biomass ntawm cov kab mob nyob hauv peb lub ntiaj teb tag nrho 1.8 1012-2.4 1012 tons ntawm cov khoom qhuav. Amino acids yog thawj monomers nyob rau hauv biosynthesis ntawm cov protein molecules, yam tsis muaj uas tib neeg thiab tsiaj txhu muaj nyob tsis tau.
Raws li cov yam ntxwv ntawm lub cev, muaj kev faib tawm ntawm tag nrho cov amino acids rau hauv cov khoom tseem ceeb, cov synthesis uas tsis tau ua nyob rau hauv tib neeg lub cev thiab tsiaj txhu. Txhawm rau kom tsis txhob muaj kev cuam tshuam hauv cov txheej txheem metabolic, nws yog ib qho tseem ceeb uas yuav tsum noj zaub mov uas muaj cov amino acids.
Nws yog cov tshuaj no yog ib hom "cib" uas yog siv los tsim cov protein ntau biopolymer. Nyob ntawm seb cov amino acid residues, nyob rau hauv dab tsi ua ntu zus lawv yuav nyob rau hauv cov qauv ntawm cov protein, cov protein uas tshwm sim muaj qee yam ntawm lub cev thiab tshuaj lom neeg thiab kev siv. Ua tsaug rau qhov muaj txiaj ntsig zoo rau cov pab pawg ua haujlwm, biochemists txiav txim siab qhov muaj pes tsawg leeg ntawm cov protein molecules, tab tom nrhiav txoj hauv kev tshiab los ua kom cov biopolymers tsim nyog rau tib neeg lub cev.
