Maltose is combination of glucose and

1. Analyze the question The question asks which monosaccharide combines with glucose to form maltose. This is about disaccharide composition.

2. Explain the concept Disaccharides are formed when two monosaccharides join by a condensation reaction, which releases one molecule of water and forms a glycosidic bond. The three common ones are:

| Disaccharide | Made up of | |---|---| | Maltose | Glucose + Glucose | | Sucrose | Glucose + Fructose | | Lactose | Glucose + Galactose |

3. Solution

• Maltose is "malt sugar", produced when enzymes such as amylase break down starch (for example in germinating barley seeds).
• Each maltose molecule contains two glucose units joined by an α-1,4 glycosidic bond.

Checking the options:

• A. Glucose: correct, since maltose = glucose + glucose.
• B. Sucrose: this is itself a disaccharide, so it cannot be a component of one.
• C. Galactose: this pairs with glucose to make lactose.
• D. Fructose: this pairs with glucose to make sucrose.

4. Answer Maltose is a combination of glucose and glucose, which is option A.

5. Exam tip Remember the pattern: "Maltose = Mono + Mono (same), Sucrose = Sweet fruit (fructose), Lactose = Looks like milk (galactose)." Another way is that only maltose is made from two identical units, which are both glucose.