Read the passage carefully and answer the questions.

Biomolecules are the organic compounds present as an essential constituents of living organisms in different cells. The molecules are generally termed as macromolecules, which are carbohydrates, enzymes, nucleic acids, amino acids and proteins etc. Carbohydrates are classified as sugars and non-sugars include sucrose, glucose, fructose, starch and cellulose. Enzymes are coordinated with various chemical reactions in nucleic acid. Nucleic acids are found in living organisms made up of proteins and natural polymers. Two types that are generally found in biological systems are DNA and RNA nucleic acid. Amino acids are bifunctional groups of carboxyl and amino groups. Proteins are a class of biologically important compounds. They are crucial to virtually all processes in living systems. Some of them are hormones, which serve as chemical messengers that coordinate certain biochemical activities.

The disaccharide present in milk is known as

Lactose

The correct answer is Option (2) → Lactose

Disaccharides are formed by the condensation of two monosaccharide units. Milk contains lactose, which is a naturally occurring disaccharide composed of glucose and galactose.

Explanation

Option 1: Sucrose

Sucrose is a disaccharide composed of glucose and fructose units linked through a glycosidic bond. It is commonly found in sugarcane and sugar beet and is known as table sugar. It is not naturally present in milk.

Option 2: Lactose

Lactose is known as milk sugar and is the primary carbohydrate present in milk. It is formed from one molecule of glucose and one molecule of galactose. It provides energy to infants and plays an important role in nutrition.

Option 3: Maltose

Maltose is a disaccharide formed by the condensation of two glucose molecules. It is produced during the digestion of starch and is commonly found in germinating grains such as barley.

Option 4: Galactose

Galactose is a monosaccharide and is one of the components of lactose. Since it is not composed of two sugar units, it is not a disaccharide.