Question

In the presence of lactase, lactose breaks down into molecules of
(a) Glucose and galactose
(b) Glucose and fructose
(c) Galactose only
(d) Glucose only

Answer 1

It is called lactase-phlorizin hydrolase, a chemical found in the small digestive tract of mammals that catalyzes the breakdown of lactose (milk sugar) into the simple sugars that are monosaccharides.

Complete answer:
Lactose is a disaccharide sugar made from galactose and glucose that is found in milk. Lactase is a protein created by numerous living beings. It is situated in the brush fringe of the small digestive tract of people and different mammals. For the complete digestion of whole milk, lactase is very essential. Lactase breaks down lactose, a sugar that gives milk its sweetness.

Additional information: Lacking lactase, individual consuming dairy items may encounter the side effects of lactose intolerance. The $\beta$-glycosidic bond in D-lactose is hydrolyzed to form D-galactose and D-glucose in metabolism, which can be absorbed with the help of the intestinal walls and into the circulation system. Hence lactase breaks down the lactose into glucose and galactose as it is formed by them.
In humans, lactase is particularly abundant during infancy. It is supposed to be a brush border enzyme and it is created by cells known as enterocytes that line the intestinal walls and form the brush border (a chemical barrier through which food must pass to be consumed).
So the right answer is 'Glucose and galactose'.

Note: Mutations in the gene that encodes lactase may bring about acquired lactase deficiency, which shows as lactose intolerance, or the inability to digest lactose. Undergoes fermentation by bacterial lactose that is not absorbed in the gastrointestinal tract which results in the production of gas and intestinal distress.