Which of these is a source of lactose?
A) potatoes
B) milk
C) sugar cane
D)sugar beets
E) starch
The Correct Answer and Explanation is :
The correct answer is B) milk.
Explanation:
Lactose is a disaccharide sugar composed of glucose and galactose. It is primarily found in the milk of mammals, including humans, and constitutes about 2–8% of milk by weight.
The other options listed do not contain lactose:
- A) Potatoes: These are rich in starch, a complex carbohydrate, but do not contain lactose.
- C) Sugar cane: This plant is a source of sucrose, commonly known as table sugar, not lactose.
- D) Sugar beets: Similar to sugar cane, sugar beets are rich in sucrose and do not contain lactose.
- E) Starch: Starch is a polysaccharide made up of glucose units and does not contain lactose.
Lactose is unique among sugars because it is the only sugar that cannot be extracted from plants; it is exclusively found in milk and dairy products.
In the human body, the enzyme lactase breaks down lactose into its constituent sugars, glucose and galactose, which can then be absorbed into the bloodstream. Some individuals have a reduced ability to produce lactase, leading to lactose intolerance, a condition where the body cannot properly digest lactose, resulting in gastrointestinal symptoms.
Understanding the sources of lactose is important, especially for individuals with lactose intolerance, as it helps in managing dietary choices to avoid discomfort.