Identify the monosaccharide that fits each of the following descriptions:
(a) in combination with glucose produces the disaccharide lactose

Verified step by step guidance

1. Understand the problem: The question asks to identify the monosaccharide that combines with glucose to form the disaccharide lactose. Lactose is a common disaccharide found in milk.
2. Recall the composition of lactose: Lactose is made up of two monosaccharides, glucose and another monosaccharide. This second monosaccharide is crucial to solving the problem.
3. Review the structure of lactose: Lactose is formed by a glycosidic bond between glucose and the monosaccharide galactose. This bond occurs between the hydroxyl groups of these two monosaccharides.
4. Connect the information: Since lactose is composed of glucose and galactose, the monosaccharide that combines with glucose to form lactose is galactose.
5. Conclude the identification: The monosaccharide that fits the description provided in the problem is galactose.

Key Concepts

Monosaccharides

Monosaccharides are the simplest form of carbohydrates, consisting of single sugar molecules. They serve as the building blocks for more complex carbohydrates, such as disaccharides and polysaccharides. Common examples include glucose, fructose, and galactose, each with distinct structures and functions in biological systems.

Disaccharides

Disaccharides are carbohydrates formed by the combination of two monosaccharides through a glycosidic bond. They play essential roles in energy storage and transport in living organisms. Lactose, for instance, is a disaccharide composed of glucose and galactose, and is found in milk.

Lactose

Lactose is a specific type of disaccharide that consists of one glucose molecule and one galactose molecule. It is primarily found in milk and dairy products and is broken down in the body by the enzyme lactase. Understanding lactose's composition is crucial for identifying its monosaccharide components.