What is the Difference Between Amylase and Lipase

The main difference between amylase and lipase is that amylase catalyzes the hydrolysis of starch, whereas lipase catalyzes the hydrolysis of lipids.

Enzymes are biological substances that act as catalysts and increase the rate of chemical reactions without being consumed in the reaction. Enzymes play a crucial role in many biological processes in the body, including digestion, metabolism, and DNA replication. Without enzymes, these processes would occur too slowly to support life. Amylase and lipase are two important enzymes involved in the digestion of food in the human body. While both enzymes play crucial roles in breaking down nutrients into their component parts, they act on different types of molecules.

Key Areas Covered

1. What is Amylase
     – Definition, Features, Function
2. What is Lipase
     – Definition, Features, Function
3. Similarities Between Amylase and Lipase
     – Outline of Common Features
4. Difference Between Amylase and Lipase
     – Comparison of Key Differences

Key Terms

Amylase, Lipase

What is Amylase

Amylase is an enzyme that catalyzes the hydrolysis of starch, giving out sugars. Amylase is present in human saliva and the saliva of some other mammals. It is present in other tissues in very small amounts. The salivary glands and the pancreas secrete this enzyme. It is considered a digestive enzyme. 

Amylase breaks down the glycosidic bonds in the starch molecules during the hydrolysis of starch. There are three main types of amylase enzymes, namely alpha, beta, and gamma amylase. These amylase types act on different parts of the starch molecule. Alpha amylase molecules are present in humans, animals, plants, and microbes, while beta amylase is present in microbes and plants. On the other hand, gamma amylase exists in animals and plants.

Higher levels of amylase are present in certain disease conditions such as decreased metabolic clearance, intestinal disease, pancreatic disease, and micro-amylasemia. This is where amylase tests are useful. Your healthcare provider might request an amylase test to diagnose and monitor the problems with the pancreas, cystic fibrosis, alcohol use disorder, eating disorder, and infection.

What is Lipase

Lipase is an enzyme that catalyzes the hydrolysis of fats. It catalyzes the hydrolysis of triglycerides into fatty acids and glycerol. The ester bonds in the triglycerides are broken down in this enzyme-catalyzed reaction.

Lipase is present in pancreatic secretions, gastric juices, intestinal juices, blood, and adipose tissue. We call the lipases in the liver hepatic lipases. Adipocytes also contain hormone-sensitive lipases. Moreover, they hydrolyze the triglycerides present in the adipose cells. Lipoprotein lipases are in the vascular endotelial surface. Lipases are also responsible for the degrading of triglycerides that circulate from chylomicrons and very low-density lipoproteins. Moreover, lipase secretions in the pancreatic secretions are responsible for the digestion and hydrolysis of fat and the absorption of fat-soluble vitamins.

Lypase is also a type of digestive enzyme. These lipases have a broad range of substrates on which they react. Some such substrates are sphingomyelinases, lipid-soluble vitamins, cholesterol, and phospholipids. But these are considered deviations from conventional lipases. Moreover, lipases are in the group alpha/beta hydrolase fold superfamily of enzymes. Lipases also play a major role in the mechanism of some cholesterol-lowering medicines.

Similarities Between Amylase and Lipase

• They both act as catalysts and increase the rate of chemical reactions without being consumed in the reaction.
• Moreover, they play a crucial role in the digestion of food and the absorption of nutrients.
• pH levels can influence both enzymes, and their optimal activity occurs within a specific pH range.

Difference Between Amylase and Lipase

Definition

Amylase is an enzyme that catalyzes the hydrolysis of starch, whereas lipase is an enzyme that catalyzes the hydrolysis of lipids.

Type of Bond

Amylases act on glycosidic bonds, while lipases act on ester bonds.

Substrates Involved

Moreover, amylases act on starch molecules, whereas lipases act on fatty acid esters such as triglycerides, oils, and fats.

Function

Amylases involve carbohydrate metabolism, whereas lipases involve lipid metabolism.

Organs that Secrete the Enzyme

Amylase is secreted by salivary glands(salivary amylase) and pancreas(pancreatic amylase), while lipase is secreted by salivary glands (salivary lipase), pancreas (pancreatic lipase), certain endothelial tissues, and the liver.

Uses

Furthermore, amylase is used as an additive, a detergent to remove starch from clothes, and in fermentation, while lipase is used in the baking industry, in producing alternative sources of energy, in laundry detergents, and as a biocatalyst.

Conclusion

In brief, enzymes are biological substances that increase the rate of a reaction without participating in the reaction. Generally, enzymes are protein molecules. Amylases and lipases are two such enzymes. The main difference between amylase and lipase is that amylase catalyzes the hydrolysis of starch, whereas lipase catalyzes the hydrolysis of lipids.

Reference:

1. “Amylase Test.” MedLine Plus.
2. “Lipase – An Overview.” Science Direct.

Image Courtesy:

1. “3-D Structure of Alpha-amylase” By MikeyB88 – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “GastricLipase” By Theislikerice – Own work (CC BY-SA 4.0) via Commons Wikimedia