Question

Starch is hydrolyzed into maltose by A. salivary amylase. B. maltase. C. pancreatic amylase. D. both (A) and (C).

Short answer

D. both (A) and (C).

Step-by-step solution

Identify the Enzymes

Recognize the enzymes mentioned in the question: salivary amylase, maltase, and pancreatic amylase. Understand their roles in digestion.

Understand Salivary Amylase

Salivary amylase is produced in the salivary glands and begins the process of breaking down starch into smaller carbohydrate molecules like maltose, starting in the mouth.

Understand Pancreatic Amylase

Pancreatic amylase is produced in the pancreas and continues the digestion of starch into maltose in the small intestine.

Rule Out Maltase

Maltase is not involved in breaking down starch into maltose; instead, it breaks down maltose into glucose.

Combine Information

Both salivary amylase and pancreatic amylase are responsible for hydrolyzing starch into maltose during digestion.

Select the Correct Answer

Based on the above information, select the option that includes both salivary amylase and pancreatic amylase.

Key concepts

salivary amylase

Salivary amylase is an important enzyme in the digestion of starch. It is produced in the salivary glands and starts working right in the mouth. When you chew your food, salivary amylase breaks down starch into smaller carbohydrate molecules like maltose. This is the first step in starch digestion and it helps to make food easier to swallow. Keep in mind that the action of salivary amylase is limited to the mouth and slightly continues in the esophagus until the food reaches the stomach.

pancreatic amylase

Pancreatic amylase takes over where salivary amylase left off. Produced by the pancreas, this enzyme is released into the small intestine. Here, it continues the digestion of starch, breaking it down further into maltose. The small intestine provides an ideal environment for pancreatic amylase because it offers a higher pH level, which is optimal for the enzyme's activity. This second stage of starch digestion is crucial for breaking down the remaining starch molecules that were not fully digested by salivary amylase.

maltase

Maltase is another enzyme involved in carbohydrate digestion, but it has a different role. Unlike salivary and pancreatic amylase, maltase does not break down starch. Instead, it works on maltose, a disaccharide produced from starch digestion. Maltase is found in the lining of the small intestine and breaks down maltose into two glucose molecules, which can then be absorbed into the bloodstream. This final step is vital for making the carbohydrate energy available for your body to use.

hydrolysis of starch

The process of breaking down starch into simpler sugars is known as hydrolysis. During hydrolysis, enzymes such as salivary amylase and pancreatic amylase add water molecules to starch, breaking the bonds between the glucose units. This turns the large, complex starch molecules into smaller, more manageable sugars like maltose. Hydrolysis is an important step in digestion, allowing the body to make use of the carbohydrate energy found in foods like bread, rice, and potatoes. Understanding hydrolysis helps you appreciate the efficiency and complexity of the digestive process.