Amylase: The Enzyme Responsible for Breaking Down Carbohydrates

The human body employs various enzymes to digest food. The primary enzyme responsible for breaking down carbohydrates is amylase. It is produced in the salivary glands and the pancreas.

Quick Summary

Amylase breaks down starches into simpler sugars the body uses for energy. Salivary amylase starts the process in the mouth. Pancreatic amylase continues in the small intestine.

Key Points

• Amylase is the primary enzyme: Both salivary and pancreatic amylase break down carbohydrates.

• Digestion starts in the mouth: Salivary amylase begins breaking down starches as you chew.

• The pancreas is a major source: Pancreatic amylase continues carbohydrate digestion in the small intestine.

• Other enzymes complete the process: Enzymes like maltase, sucrase, and lactase break down smaller sugar molecules at the intestinal brush border.

• Carbohydrates are converted to energy: This process converts carbs into monosaccharides (like glucose) for energy.

What Is Amylase?

Amylase is a digestive enzyme, a type of carbohydrase, that specializes in breaking down carbohydrates. It hydrolyzes glycosidic bonds within carbohydrate chains. This converts complex starches into smaller sugar molecules, like maltose and dextrin. These can then be further broken down and absorbed by the body.

Two main types of amylase are crucial for human digestion:

• Salivary amylase: Found in saliva, it's the first line of defense against complex carbohydrates. It begins breaking down starch into simpler sugars as you chew. Starchy foods can taste sweet if chewed for a long time. However, its activity stops in the acidic stomach.
• Pancreatic amylase: Produced by the pancreas and released into the small intestine, it continues the breakdown of starches not fully digested in the mouth. It works in the slightly alkaline environment of the small intestine to complete the digestion of complex carbohydrates.

The Complete Breakdown of Carbohydrates

Amylase is the main enzyme, but it doesn't act alone in breaking down all carbohydrates. Other carbohydrase enzymes work on the smaller sugar molecules produced by amylase. These enzymes, located on the brush border of the small intestine, ensure carbohydrates are fully broken down into monosaccharides.

Here are some of these crucial accessory enzymes:

• Maltase: Breaks down maltose into two glucose molecules.
• Sucrase: Breaks down sucrose into glucose and fructose.
• Lactase: Breaks down lactose into glucose and galactose.
• Isomaltase: Cleaves branching bonds in starches that amylase cannot break, converting them into glucose.

The Journey of Carbohydrate Digestion

The entire carbohydrate digestion process is a multi-step journey through the digestive system.

1. In the Mouth: Mechanical digestion breaks down food into smaller pieces as you chew. Salivary amylase begins the chemical digestion of starches.
2. In the Stomach: Food travels to the stomach. The acidic environment deactivates salivary amylase, stopping carbohydrate digestion.
3. In the Small Intestine: Stomach contents move into the duodenum. The pancreas secretes pancreatic amylase, and digestion resumes.
4. At the Brush Border: Enzymes like maltase, sucrase, and lactase break down remaining disaccharides into simple sugars.
5. Absorption: Monosaccharides like glucose, fructose, and galactose are absorbed through the small intestine and enter the bloodstream, going to cells for energy.

Comparison of Major Digestive Enzymes

Here's a comparison of amylase to enzymes that break down other macronutrients.

Feature	Amylase	Protease (e.g., Pepsin, Trypsin)	Lipase
Function	Breaks down complex carbohydrates (starches) into simpler sugars.	Breaks down proteins into smaller peptides and amino acids.	Breaks down fats (lipids) into fatty acids and glycerol.
Primary Production Sites	Salivary glands and pancreas.	Stomach and pancreas.	Pancreas and small intestine.
Location of Action	Mouth and small intestine.	Stomach and small intestine.	Small intestine.
Substrate	Starch and other complex carbohydrates.	Proteins and polypeptides.	Lipids (fats and oils).
Optimum pH	Slightly alkaline (6.7–7.0) in the mouth, and alkaline in the small intestine.	Acidic in the stomach, and alkaline in the small intestine.	Alkaline in the small intestine, assisted by bile.

Conclusion

Amylase is essential for processing dietary carbohydrates. Found in both saliva and pancreatic juice, it initiates and continues breaking down starches into smaller sugars. Supported by other carbohydrases in the small intestine, amylase helps the body efficiently harvest energy from carbohydrates. Understanding amylase is key to understanding human nutrition and the digestive processes that fuel our daily lives.

Learn more about human digestion from the National Institutes of Health.

Frequently Asked Questions

What is amylase, and where is it produced?

Amylase is a digestive enzyme that breaks down starches into simpler sugars. It is primarily produced by the salivary glands and the pancreas.

How does amylase break down carbohydrates?

Amylase hydrolyzes glycosidic bonds in starches, breaking down long chains into smaller sugar molecules, like maltose and dextrin.

Why does carbohydrate digestion stop in the stomach?

Salivary amylase is active in the mouth, but the stomach's acidic pH deactivates it. Digestion pauses in the stomach and resumes in the small intestine.

What other enzymes are involved in carbohydrate digestion?

Enzymes like maltase, sucrase, and lactase, located on the small intestine's brush border, break down remaining sugar molecules.

What happens if there is an amylase deficiency?

An amylase deficiency can cause poor carbohydrate digestion, leading to bloating, gas, and diarrhea from undigested starches.

How do amylase levels indicate health problems?

High blood amylase levels can indicate pancreatic issues, like pancreatitis, where the inflamed pancreas leaks the enzyme.

Can I increase my amylase levels naturally?

A healthy, balanced diet and chewing food thoroughly can support your body's own enzyme production.