Lactose yog ib qho disaccharide pom nyob rau hauv cov khoom noj mis nyuj mis nyuj, muaj ib qho molecule ntawm qabzib thiab ib lub molecule ntawm galactose. Nws yog cov khoom tseem ceeb ntawm lactose, cov khoom noj tseem ceeb rau tib neeg thiab lwm yam tsiaj txhu thaum cev xeeb tub. Lactose ua haujlwm tseem ceeb hauv tib neeg lub cev. Nws yog ib qhov chaw muaj zog.