Digestive enzymes play a crucial role in the digestive system by breaking down complex food substances into simpler molecules that can be easily absorbed and utilized by the body. Each type of digestive enzyme targets specific nutrients and breaks them down into their basic components. Here are the primary functions of various digestive enzymes:


Produced in the Salivary glandsSalivary glands are exocrine glands located in the mouth that produce saliva, a key component in the initial stages of digestion. They moisten food, facilitating chewing and swallowing, and contain enzymes like amylase that begin the breakdown of starches. Saliva also helps in oral hygiene by neutralizing acids and washing away food particles. and the pancreas, amylase breaks down carbohydrates (starches and sugars) into simpler sugars like maltose and dextrin. Salivary amylase starts the process in the mouth, and pancreatic amylase continues it in the small intestine.

Protease (or Pepsin in the Stomach)

These enzymes are responsible for breaking down proteins into peptides and amino acids. PepsinPepsin is a digestive enzyme produced in the stomach that breaks down proteins into smaller peptides. It is first secreted as an inactive enzyme, pepsinogen, which is then activated by stomach acid into pepsin. This activation is crucial for the efficient digestion of dietary proteins, aiding in nutrient absorption., which works in the acidic environment of the stomach, initiates protein digestion. Other proteases, like trypsin and chymotrypsin, are secreted by the pancreas and act in the small intestine.

Lipase and Lactase

Lipase: Produced primarily by the pancreas, lipase breaks down fats (lipids) into fatty acids and glycerol. It is essential for the digestion of dietary fats and is most effective in the small intestine, where the environment is suitable for its action.
Lactase: This enzyme is responsible for breaking down lactose, the sugar found in milk, into glucose and galactose. Lactase is produced by the lining of the small intestine.


Although humans do not produce cellulase, it is worth mentioning as it breaks down cellulose, a plant fiber. Some microorganisms in the human gut can produce cellulase, aiding in the breakdown of fiber.

Nucleases (Ribonuclease and Deoxyribonuclease)

These enzymes, secreted by the pancreas, break down nucleic acids (RNA and DNA) into nucleotides. The action of these enzymes ensures that nutrients like carbohydrates, proteinsProteins are large, complex molecules made up of amino acids, essential for the structure, function, and regulation of the body’s cells, tissues, and organs. They play critical roles in processes like muscle contraction, immune response, and enzyme activity. Proteins are vital for growth, repair, and overall body maintenance., fats, and nucleic acids are broken down into their simplest forms (sugars, amino acids, fatty acids, glycerol, and nucleotides, respectively). These simpler molecules are then absorbed through the intestinal wall into the bloodstream and transported to various cells in the body, where they are used for energy, growth, and repair.

The proper functioning of digestive enzymes is essential for good nutrition and overall health. Deficiencies or malfunctions in these enzymes can lead to digestive disorders and malabsorption issues.

More about Digestive enzymes
Digestive enzymes are specialized proteins that play a crucial role in breaking down food into nutrients that the body can absorb and utilize. These enzymes are secreted by different parts of the digestive system, including the salivary glands, stomach, pancreas, and small intestine. Each enzyme targets specific types of nutrients: amylases break down carbohydrates, proteases work on proteins, and lipases are responsible for fats. By breaking down complex molecules into simpler ones, these enzymes ensure that the body can absorb essential nutrients like sugars, amino acids, and fatty acids.

The process of digestion involving these enzymes is highly coordinated and begins in the mouth with salivary amylase starting the breakdown of carbohydrates. In the stomach, pepsin (activated from pepsinogen in the presence of stomach acid) continues the digestion of proteins. The pancreas plays a vital role by secreting a cocktail of enzymes into the small intestine, where most of the digestion and absorption occur.

These include pancreatic amylase for carbohydrates, trypsin and chymotrypsin for proteins, and pancreatic lipase for fats. The proper functioning of these enzymes is essential for good digestive health, and deficiencies or malfunctions can lead to various digestive disorders.

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List of Questions of Class 10 Science Chapter 5

Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans?
What criteria do we use to decide whether something is alive?
What are outside raw materials used for by an organism?
What processes would you consider essential for maintaining life?
What are the differences between autotrophic nutrition and heterotrophic nutrition?
Where do plants get each of the raw materials required for photosynthesis?
What is the role of the acid in our stomach?
What is the function of digestive enzymes?
How is the small intestine designed to absorb digested food?
What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?
What are the different ways in which glucose is oxidised to provide energy in various organisms?
How is oxygen and carbon dioxide transported in human beings?
How are the lungs designed in human beings to maximise the area for exchange of gases?
What are the components of the transport system in human beings?
Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?
What are the components of the transport system in highly organised plants?
How are water and minerals transported in plants?
How is food transported in plants?
Describe the structure and functioning of nephrons.
What are the methods used by plants to get rid of excretory products?
How is the amount of urine produced regulated?
How are fats digested in our bodies? Where does this process take place?
What is the role of saliva in the digestion of food?
What are the necessary conditions for autotrophic nutrition and what are its byproducts?
What are the differences between aerobic and anaerobic respiration?
How are the alveoli designed to maximise the exchange of gases?
What would be the consequences of a deficiency of haemoglobin in our bodies?
Describe double circulation of blood in human beings. Why is it necessary?
What are the differences between the transport of materials in xylem and phloem?
Compare the functioning of alveoli in the lungs and nephrons in the kidneys with respect to their structure and functioning.

Last Edited: November 16, 2023