Problem 10 - 43 Years JEE ADVANCED (1978-2020) + JEE MAIN Chapterwise & Topicwise Solved Papers Chemistry

Question

Which of the following enzyme converts starch into maltose? [Main Online April 9, 2013] (a) Diastase (b) Maltase (c) Zymase (d) Invertase

Step-by-Step Solution

Answer

Diastase.

Step 1: Understanding the Question

The question asks us to identify which enzyme is responsible for converting starch into maltose. Starch is a polysaccharide, and maltose is a disaccharide sugar consisting of two glucose units.

Step 2: Examining the Enzymes

We are given four different enzyme options: Diastase, Maltase, Zymase, and Invertase. Each enzyme has specific roles: - **Diastase**: Converts starch into maltose. - **Maltase**: Converts maltose into glucose. - **Zymase**: Involved in the fermentation process, converting sugars into alcohol and carbon dioxide. - **Invertase**: Converts sucrose into glucose and fructose.

Step 3: Identifying the Correct Enzyme

Diastase is the enzyme responsible for breaking down starch into maltose. None of the other enzymes listed are involved in the conversion of starch to maltose.

Step 4: Conclusion

Based on the understanding of the enzymes and their functions, the enzyme that converts starch into maltose is Diastase (option a).

Key Concepts

Starch to Maltose Conversion

The process of converting starch to maltose is a fundamental biochemical reaction that occurs during the digestion of carbohydrates. Starch, a polysaccharide, is a large molecule composed of many glucose units linked together. To be utilized by the body, these complex molecules must be broken down into simpler sugars.

• Starch is a major carbohydrate source found in foods like potatoes, rice, and bread.
• Maltose, on the other hand, is a disaccharide sugar, meaning it's composed of two glucose molecules.
• This breakdown is crucial as only simple sugars can be absorbed into the bloodstream for energy.

To achieve this conversion, specific enzymes play essential roles. The enzyme diastase is key in this transformation, ensuring that the large starch molecules are reduced to maltose. This reaction is an integral step in carbohydrate digestion and energy metabolism.

Diastase Function

Diastase is an important enzyme known for its capability to catalyze the conversion of starch into maltose. Discovered in the early 19th century, this enzyme plays a pivotal role in the digestive processes, particularly those involving carbohydrates. Diastase operates by breaking the alpha-linkages in starch molecules.

• Produced naturally in plants and certain seeds during germination.
• Also found in saliva, where it aids in the initial stage of digestion.
• Converts complex starches into simpler sugars like maltose, which can then be further broken down into glucose.

The presence of diastase is fundamental in numerous industrial applications, such as in the brewing and baking industries, where the conversion of starch is necessary to produce sugars that yeast can ferment. Understanding its role helps us appreciate the intricate processes that occur in both natural and commercial settings.

Disaccharides

Disaccharides are a type of carbohydrate composed of two monosaccharide molecules linked together. They are crucial dietary sugars and include maltose, lactose, and sucrose.

• Maltose is formed from two glucose units and often results from the breakdown of starch by enzymes like diastase.
• Lactose, found in milk, is made up of glucose and galactose.
• Sucrose, common table sugar, consists of glucose and fructose.

Disaccharides must be broken down into their monosaccharide components to be absorbed by the body. This task is carried out by specific enzymes:

• Maltase breaks down maltose into glucose.
• Lactase processes lactose into glucose and galactose.
• Invertase converts sucrose into glucose and fructose.

A solid understanding of disaccharides and their enzymatic breakdown is important for comprehending human digestion and the nutritional properties of foods.