Difference Between Amylase and Amylose

Main Difference – Amylase vs Amylose

Amylase is an enzyme. It can catalyze the hydrolysis of starch molecules. Amylose is a carbohydrate. It is a major constituent of starch. Therefore, amylase can catalyze the hydrolysis or the breakdown of amylose in starch. Although the names amylase and amylose sounds similar, there is a significant difference between amylase and amylose as discussed below in this article. The main difference between amylase and amylose is that amylase is a protein whereas amylose is a carbohydrate. Both of these compounds have different important roles in our body.

Key Areas Covered

1. What is Amylase
      – Definition, Structure, Role in Our Body
2. What is Amylose
      – Definition, Structure, Role in Our Body
3. What is the Difference Between Amylase and Amylose
      – Comparison of Key Differences

Key Terms: Amylase, Alpha Amylase, Amylose, Beta Amylase, Carbohydrate, Enzyme, Hydrolysis, Gamma Amylase, Protein, Starch

What is Amylase

Amylase is an enzyme that can catalyze the hydrolysis of starch. The hydrolysis of starch is the breakdown of starch molecules into smaller carbohydrates. Starch is composed of amylose and amylopectin. The alpha-1,4-glycosidic bonds in those molecules can be broken down in the presence of amylase. This enzyme can be found in our saliva.

Since amylase is an enzyme, it is a protein. It is made up of a number of amino acids. It has a complicated structure that is categorized as tertiary protein structure. There are hydrogen bonds, hydrophobic bonds, disulfide bonds, ionic bonds and Van Der Waal bonds present in this structure. There are three types of amylase structures classified according to the way they attack chemical bonds.

Types of Amylase

Alpha Amylase
Beta Amylase
Gamma Amylase

Figure 1: Complicated Structure of Salivary Alpha Amylase Enzyme

Most amylases present in our body are alpha-amylases. They are found in our digestive system (ex: produced in salivary amylases and pancreatic amylases). Salivary amylases mix with food and start the digestion of starch. Since it is mixed with food, salivary amylases move to the stomach along with food and continue to hydrolyze starch. Beta-amylase can be found in other organisms such as fungi, yeasts, bacteria, etc. Gamma amylase can cleave alpha-1,6-glycosidic bonds as well.

What is Amylose

Amylose is a carbohydrate that is composed of a number of glucose molecules linked to each other via 1,4-glycosidic bonds. Amylose molecules are made out of alpha-D-glucose. Amylose is one of the two major components of starch.

Figure 2: Chemical Structure of Amylose

Amylose is a linear straight chain polysaccharide of glucose. The number of glucose units present in amylose may vary from 300 to many thousands. Here, the straight chain is formed due to the formation of a chemical bond between carbon-1 and carbon-4 of two glucose molecules.

It is not soluble in cold water. Amylose can be degraded into smaller carbohydrate molecules such as maltose. This is done in the starch hydrolysis reaction. Here, starch is broken down into smaller carbohydrates in the presence of amylase enzyme.

Amylose is an important plant energy source. It acts as a storage carbohydrate. Since amylose is a linear structure, it takes less space. Therefore, it is the preferred storage carbohydrate form in plants. Amylose is very important in food items that are made using starch. Amylose act as a thickener, water binder, emulsion stabilizer and a jelling agent.

Definition

Amylase: Amylase is an enzyme that can catalyze the hydrolysis of starch.

Amylose: Amylose is a carbohydrate composed of a number of glucose molecules linked to each other via 1,4-glycosidic bonds.

Structure

Amylase: Amylase has a tertiary structure of protein.

Amylose: Amylose has a linear straight chain structure.

Monomer

Amylase: Amylase molecules are made out of amino acids.

Amylose: Amylose molecules are made out of glucose units.

Role in Biological Systems

Amylase: Amylase can catalyze the hydrolysis of starch.

Amylose: Amylose can act as a storage carbohydrate in plants.

Occurrence

Amylase: Amylase can be found in saliva and pancreatic secretions.

Amylose: Amylose can be found in starch (in plants).

Conclusion

Amylase and amylose are important compounds that can be found in biological systems such as the human body. Although the spellings of two terms are nearly similar, they are totally different compounds. The main difference between amylase and amylose is that amylase is a protein whereas amylose is a carbohydrate.

References:

1. “Amylase.” Encyclopædia Britannica, Encyclopædia Britannica, inc., 31 May 2013, Available here.
2. “Amylose: Structure, Formula & Function.” Study.com, Available here.
3. “Amylose.” Wikipedia, Wikimedia Foundation, 9 Oct. 2017, Available here.

Image Courtesy:

1. “Salivary alpha-amylase 1SMD” By Own work. – From PDB entry 1SMD. (Public Domain) via Commons Wikimedia
2. “Amylose 3Dprojection.corrected” By glycoform – Own work (Public Domain) via Commons Wikimedia