Qhov Tseem Ceeb Qhov txawv - Acid vs Basic Amino Acids
Amino acids yog lub tsev tsim cov proteins. Cov saw hlau ntawm cov amino acids hu ua polypeptide thiab kev sib xyaw ntawm ntau cov saw hlau polypeptide tsim cov protein molecule. Qhov sib txawv tseem ceeb ntawm cov kua qaub thiab cov amino acids yooj yim yog cov amino acids acidic muaj cov kab mob acidic thaum cov amino acids yooj yim muaj cov kab sib txuas ntawm nruab nrab pH.
Ib qho amino acid molecule muaj plaub ntu; ib pawg carboxylic acid, pawg amine, hydrogen atom thiab "R" (alkyl) pawg. Cov plaub pawg no yog sib txuas ncaj qha rau lub hauv paus carbon atom. Pab pawg "R" yog lub npe hu ua cov saw hlau sab hauv cov amino acid.
Acidic Amino Acids yog dab tsi?
Acidic amino acids yog polar amino acids uas muaj tus nqi tsis zoo ntawm pH nruab nrab. Qhov kev tsis zoo no tshwm sim hauv pawg sab (R pawg) ntawm cov amino acid. Cov kab txuas sab no muaj cov pawg carboxylic acid uas tsis yog pawg carboxylic acid ncaj qha mus rau hauv nruab nrab carbon atom. Cov chains sab no hu ua acidic side chains vim tias cov nqi tsis zoo no yog tsim los ntawm kev poob ntawm protons (hydrogen ions) los ntawm pawg carboxylic nyob rau hauv cov saw hlau sab. Ntawm 20 qhov tseem ceeb amino acids, ob amino acids yog acidic amino acids; aspartate thiab glutamate.
Cov pKa ntawm ob cov amino acids no tsawg txaus kom poob ib qho proton ntawm nruab nrab pH thiab ua rau tsis zoo. (PKa yog ib qho kev ntsuas ntawm cov kua qaub zog ntawm cov kua qaub; me dua pKa, siab dua cov acidity. Yog li ntawd, cov tebchaw uas muaj pKa qhov tseem ceeb tau yooj yim tso tawm protons).
Daim duab 01: Aspartate thiab Glutamate yog Acidic Amino Acids
Acidic amino acids paub los ua kom lub hauv paus paj hlwb ntawm tib neeg lub cev. Aspartate thiab glutamate yog ib qho tseem ceeb excitatory neurotransmitters nyob rau hauv mammalian central paj hlwb.
Amino Acids yog dab tsi?
Basic amino acids yog polar amino acids uas muaj tus nqi zoo ntawm pH nruab nrab. Cov amino acids no muaj cov kab sib txuas yooj yim (R pawg). Qhov tseem ceeb no tshwm sim vim muaj cov pab pawg amine nyob rau hauv cov saw hlau sab (tshwj tsis yog cov pab pawg amine ncaj qha rau hauv nruab nrab carbon atom).
Muaj peb yam amino acids ntawm 20 qhov tseem ceeb amino acids; arginine, lysine thiab histidine. Cov kab sib txuas ntawm cov amino acids no muaj ntau cov nitrogen atoms qhia tias muaj ntau pawg amine. Amine pawg yog qhov yooj yim. Yog li, lawv ua rau lub hauv paus ntawm amino acid molecule. Cov pKa ntawm cov amino acids no siab txaus los txais cov protons. Cov pab pawg amine nyob rau hauv cov saw hlau yooj yim khi protons. Qhov kev khi ntawm cov protons ntxiv no muab cov amino acid molecule ib qho txiaj ntsig zoo vim tias cov protons raug them zoo.
Qhov txawv ntawm Acid thiab Basic Amino Acids yog dab tsi?
Acidic vs Basic Amino Acids |
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| Acidic amino acids yog polar amino acids uas muaj tus nqi tsis zoo ntawm nruab nrab pH. | Basic amino acids yog polar amino acids uas muaj tus nqi zoo ntawm pH nruab nrab. |
| Sab Chains | |
| Acidic amino acids muaj acidic sab chains. | Basic amino acids muaj cov kab txuas yooj yim. |
| Acidic amino acids muaj tus nqi tsis zoo ntawm nruab nrab pH. | Basic amino acids muaj tus nqi zoo ntawm pH nruab nrab. |
| pKa | |
| PKa ntawm acidic amino acids yog tsawg. | PKa ntawm cov amino acids yog siab. |
| Nature | |
| Acidic amino acids tuaj yeem tso tawm protons. | Basic amino acids tuaj yeem txais protons. |
Summary –Acidic vs Basic Amino Acids
Amino acids yog cov molecules me me uas dhau los ua polymerization los ua cov protein molecules. Muaj ob yam tseem ceeb ntawm cov amino acids li acidic amino acids thiab cov amino acids yooj yim. Qhov sib txawv ntawm acidic thiab yooj yim amino acids yog tias acidic amino acids muaj acidic sab chains whereas cov amino acids yooj yim muaj cov sab chains ntawm nruab nrab pH.
