Urea vs zis
Muaj qhov sib txawv ntawm urea thiab zis txawm tias ob qho tib si raug suav tias yog cov khoom pov tseg nitrogenous uas tau tawm los ntawm cov zis hauv cov tsiaj. Metabolism ntawm cov amino acids thiab nucleic acids ua rau nitrogenous khib nyiab. Thaum cov kua qaub no metabolized, ammonia yog tsim los ntawm cov khoom tam sim ntawd, uas yog tshuaj lom heev rau cov hlwb thiab yuav tsum tau tawm ntawm lub cev. Cov tsiaj zoo li cov ntses pob txha thiab ntau cov dej tsis muaj pob txha tshem tawm lawv cov khoom siv nitrogenous ncaj qha raws li ammonia. Txawm li cas los xij, hauv cov tsiaj txhu, amphibians thiab cov ntses cartilaginous, ammonia tau hloov pauv sai sai rau hauv urea los ntawm lawv lub siab thiab tso tawm raws li cov zis los ntawm cov kab mob excretory. Urea muaj tshuaj lom tsawg dua thaum piv rau ammonia. Cov noog thiab cov tsiaj reptiles tso tawm lawv cov nitrogenous pov tseg hauv daim ntawv ntawm uric acid. Txawm hais tias kev tsim cov uric acid koom nrog ntau lub zog, nws txuag dej ntau.
YUrea yog dab tsi?
Urea thawj zaug pom thiab cais tawm ntawm tib neeg cov zis hauv xyoo 1773 los ntawm H. M. Rouelle. Urea suav hais tias yog cov organic tseem ceeb ntawm tib neeg. Nws yog tsim nyob rau hauv thawj theem nyob rau hauv lub siab raws li ib tug tshwm sim ntawm cov amino acid metabolism. Thaum pib tsim ammonia yog thawj zaug hloov mus rau hauv urea hauv daim siab hlwb thiab tsim urea yog taug kev los ntawm cov ntshav mus rau ob lub raum. Hauv lub raum, urea yog lim tawm ntawm cov ntshav thiab tawm nrog cov zis los ntawm cov zis. Txij li thaum, urea yog synthesized los ntawm cov amino acid metabolism, tus nqi ntawm urea nyob rau hauv cov zis qhia txog tus nqi ntawm cov protein degradation. Ib lub molecule ntawm urea muaj ob pawg -NH2 txuas nrog carbonyl (C=O) pawg, ua rau cov tshuaj formula ntawm CO (NH₂)₂. Urea yog dav siv los ua chiv, uas muab nitrogen rau cov nroj tsuag. Tsis tas li ntawd, nws kuj tseem siv cov khoom siv raw hauv qee qhov kev lag luam tshuaj xws li resins, tshuaj, thiab lwm yam.
tso zis yog dab tsi?
Tsuas yog cov tsiaj nyeg, amphibians thiab cov ntses cartilaginous tso lawv cov nitrogenous pov tseg hauv daim ntawv tso zis. Cov zis yog tsim nyob rau hauv lub raum los ntawm ib tug txheej txheem hu ua tso zis. Cov zis yog tsim los ntawm cov dej feem ntau (kwv yees li 95%) thiab lwm yam dej soluble organic thiab inorganic compounds. Cov ntsiab lus tseem ceeb hauv cov zis muaj xws li urea, uric acid, creatinine, amino acid derivatives (hippurate), urochromes (tsim los ntawm hemoglobin degradation), cov tshuaj hormones (catecholamines, steroids thiab serotonin), qabzib, ketone lub cev, proteins thiab lwm yam. Cov khoom tseem ceeb hauv cov zis yog cov cations (Na+, K+, Ca2+, Mg2+, and NH4+) and anions (Cl–, SO, SO 42-, and HPO42-). Thaum tag nrho cov ion concentration raug txiav txim siab, Na+ thiab Cl– sawv cev rau ob feem peb ntawm tag nrho cov electrolytes hauv cov zis.
Ib tug neeg laus feem ntau tsim cov zis 0.5 txog 2.0 L ib hnub. Cov zis muaj pes tsawg leeg yog nyob ntawm qhov muaj pes tsawg leeg ntawm cov khoom noj thiab cov dej kom tsawg. Cov zis muaj pes tsawg leeg thiab nws cov tsos yog siv los txheeb xyuas qee yam kab mob. Piv txwv li, muaj cov piam thaj ntau thiab ketone lub cev tuaj yeem siv los kuaj mob ntshav qab zib mellitus. Tsis tas li ntawd, muaj lossis tsis muaj hCG (chorionic gonadotropin) hauv cov zis tuaj yeem siv rau kev kuaj cev xeeb tub.
Urea thiab tso zis yog dab tsi?
• Urea yog thawj zaug tsim hauv lub siab los ntawm cov metabolism hauv nucleic acids thiab amino acids. Txawm li cas los xij, cov zis yog tsim nyob rau hauv ob lub raum los ntawm kev tso zis.
• Urea yog cov organic tseem ceeb hauv cov zis.
• Urea yog ib yam khoom, tab sis cov zis yog sib xyaw ntawm ntau yam.
• Urea tuaj yeem pom tau ua ib qho khoom, tab sis cov zis muaj nyob ua kua.
• Tus nqi ntawm urea hauv cov zis qhia txog cov protein degradation hauv lub cev.
