Question

Lactose is composed of
A. Glucose + glucose
B. Glucose + galactose
C. Glucose + fructose
D. Fructose + galactose.

Answer 1

Hint: Lactose come under carbohydrates, it is a disaccharide, where lactose is the large complex molecules that are formed by 2 simple molecules or by 2 monosaccharides, while the lactose in the intestine is absorbed, only if they split into simple molecules.

Complete answer:
Lactose is white, water-soluble, non- hygroscopic solid, and mildly sweet in taste, and it is majorly used in the food industry.
Lactose is the condensation of the two molecules, such as glucose and galactose, where these simple molecules are held together by beta 1-4 glycosidic linkage.
In mammals, all infants obtain nutrition by milk from mother, which contain lactose, and the intestine of the infants produce the enzyme called lactase which breaks the lactose to glucose and galactose and helps in absorption, but in adults, due to the stoppage of the consumption, slowly the production of lactase enzyme is decreased.
The sweetness of lactose ranges from 0.2 to 0.4, and it is a carbohydrate, which is digested in the small intestine, usually the caloric value is 2 to 4kcal/gm, based on the lactose consumed and the enzyme produced in the intestine.
Undigested lactose in the intestine acts as dietary fiber, which is helpful for the absorption of calcium and magnesium.
The glycemic index of lactose is 40 to 60 and it causes less cariogenicity among all sugars.

Note:
Some people do not produce lactase or stop producing it, in those people lactose is absorbed and the condition is called lactose intolerance, where after the consumption, within a half-hour, the person may show the symptoms of diarrhea, bloating, etc. In order to avoid these people with lactose intolerance should avoid lactose-containing food, like dairy products, etc.