Cov zaub mov nqaij qaib yuav tsum muaj qhov sib npaug ntawm cov amino acids tseem ceeb los txhawb kev loj hlob sai thiab kev loj hlob. Lysine, methionine, thiab threonine yog cov tseem ceeb tshaj plaws, vim lawv ncaj qha cuam tshuam rau cov leeg nqaij protein synthesis thiab pub hloov pauv hloov pauv. Methionine, tshwj xeeb, yog ib qho kev txwv cov amino acid hauv cov nqaij qaib pub, txhais tau tias nws qhov tsis muaj peev xwm tuaj yeem cuam tshuam kev loj hlob txawm tias lwm cov as-ham muaj ntau. Los ntawm kev ntxiv nrog cov amino acids hluavtaws, cov neeg tsim khoom tuaj yeem tsim cov khoom noj uas ua tau raws li cov noog xav tau kev noj haus yam tsis muaj kev cia siab rau cov khoom noj muaj txiaj ntsig zoo li cov taum noj mov lossis ntses ntses. Qhov no tsis yog tsuas yog txo cov nqi pub khoom noj xwb tab sis kuj txo qis nitrogen excretion, pab txhawb kev ua liaj ua teb kom ruaj khov.