Digestion
Digestion means a person's ability to digest food. Under this process food is treated with heat, enzymes, or a solvent to promote decomposition or to extract essential components from food. Under this process breakdown of large insoluble food molecules into small water-soluble food molecules so that they can be absorbed into the watery blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the bloodstream. During all these processing the digestive system/tract plays a very crucial role. The digestive tract is a long tube-like structure that starts with the mouth and ends in the large intestine.
Apart from this there are so many digestive enzymes present in our digestive tract which help in the digestion process and make digestion easier. Digestive enzymes help in the digestion of complex food into simpler forms and these digestive enzymes are produced by different parts of the digestive tract.
There is Mainly Two Process of Digestion Which Happen in Mouth, They are:
Mastication: this is done with the help of mouth, tongue and saliva.
Lubrication of Food: under this process masticated food is converted into bolus with the help of salivary enzymes.
Different Types of Digestive Enzymes
There are mainly three main types of Digestive Enzymes present in our body. They’re grouped based on the reactions they catalyse:
Amylase Enzyme: They break down starches and carbohydrates into sugars.
Protease Enzyme: it breaks down proteins into amino acids.
Lipase Enzyme: It breaks down lipids, which are fats and oils, into glycerol and fatty acids.
Nuclease Enzyme: They break nucleic acid into nucleotides.
Function of Different Digestive Enzymes along with their Secretion Location
Different Types of Digestive Enzymes produced inside the Mouth, they are:
Lipase Enzyme: digestion of lipids is initiated in the mouth lipase starts the digestion of the lipids/fats.
Salivary Amylase: digestion of carbohydrates also initiated in the mouth. Amylase, produced by the salivary glands, breaks complex carbohydrates to smaller chains, or even simple sugars. It is sometimes called ptyalin.
Lysozyme: Food contains nonessential nutrients, e.g. bacteria or viruses, it acts as an antimicrobial agent.
Different Types of Digestive Enzymes are Produced Inside Stomach, they are:
Pepsin: It is the main gastric enzyme. It is produced by the stomach cells called "chief cells" in its inactive form they are known as pepsinogen. Pepsinogen is then activated by the stomach acid into its active form, known as pepsin.
Function: It helps in breaking down protein in the food into smaller particles known as peptide and amino acids. First step of protein digestion occurs in the stomach, whereas digestion of carbohydrates and lipids starts in the mouth.
Gastric Lipase: It is an acidic lipase secreted by the gastric chief cell in the fundic region of mucosa in the stomach. Optimum pH for gastric lipase is in between 3-6.
Function: It is responsible for digestion of dietary fat present in our stomach.
Hydrochloric Acid(HCL): It helps to denature the ingested protein and kill any bacteria and virus that remains in food, it also helps in activating pepsinogen to convert them into pepsin.
Intrinsic Factor: It is produced by parietal cells of the stomach. Itself in transformation and absorption of various micronutrients.
Mucin: It is highly acidic in nature and destroys different bacteria and viruses present in food.
Gastrin: This hormone is produced by the G-cell of the stomach and it is mainly an endocrine hormone. It stimulates parietal cells for HCL production and production of several intrinsic factors.
Role of Pancreas in Digestion Process
Pancreas secretes pancreatic juice and this pancreatic juice contain various digestive enzymes, they are:
Trypsinogen: they are present in inactive form, once they are activated they are converted into trypsin, which helps in breakdown of protein. Trypsinogen is activated with the help of enterokinase enzyme.
Chymotrypsinogen: It is present in inactive form and with the help of enterokinase it is converted into active chymotrypsin.
Carboxypeptidase: It is a protease that takes the terminal amino acid group from protein.
Pancreatic Lipase: It degrades triglycerides into two fatty acids and a monoglyceride.
Cholecystokinin: It is a unique peptide released by duodenal I- cells, they are also produced in response to chyme containing high fat.
Enzymes Produced by Small Intestine
There are various digestive enzymes which are produced by small intestine, they are:
Secretin: It is an endocrine hormone produced by the duodenal S type cell in response to decreased acidity of gastric chyme.
Cholecystokinin (CCK): It is a unique peptide released by the duodenal "I cells" in response to chyme containing high fat or protein content. It also increases gallbladder contraction, causing release of pre-stored bile into the cystic duct, and eventually into the common bile duct and via the ampulla of vater into the second anatomic position of the duodenum.
Gastric Inhibitory Peptide (GIP): It is a kind of peptide that decreases gastric motility and is produced by duodenal mucosal cells.
Multiple Choice Questions
1. Which of the following matches between Digestive Enzyme and Molecule Digested is incorrect?
Protease - Peptide
Amylase - Carbohydrate
Lipase - Fats
Amylase - Starches
Answer: (2)
2. Which of the following statements about the location of Digestive Enzymes is true?
The majority of digestive enzymes' work is done in the small intestine
Proteases are found only in the stomach
Most digestive enzymes are produced in the small intestine
The pancreas is part of the alimentary canal, and the source of many digestive enzymes.
Answer: (2)
Interesting Facts
As you grow older, the enzyme production in your body tends to decrease.
Your lifestyle and the type of diet you consume regularly makes a lot of difference with regard to the digestive enzymes in your body.
One of the best ways to keep your digestive tract in shape is through engaging in aerobic exercises on a regular basis.
Besides breaking down the food into various nutrients in your body, digestive enzymes also help to fight off certain bacterias and diseases.
FAQs on Role of Digestive Enzymes
1. What are digestive enzymes? What are the different types of digestive enzymes and their functions?
The digestive tract produces various types of digestive enzymes that help one with their process of digestion of complex food particles into a much simpler form.
There are different types of digestive enzymes based on their location of secretion. Some of the most imperative ones are as follows:
Amylase: It helps with the digestion of carbohydrates by breaking down starch into sugar.
Lipase: The breaking down of fats into fatty acids along with glycerol is looked after by this digestive enzyme.
Maltase: This helps in breaking down malt, i.e., malt sugar, into glucose or simple sugar, which then, is either almost instantly utilised by the body or is stored as glycogen in the liver for future utilisation.
Lactase: Lactose is broken down into simple sugars like glucose and galactose with the help of lactase.
- Sucrase: This is mainly responsible for breaking down sucrose into fructose as well as glucose so as to make it easier for the body to absorb such simple sugars
2. Explain four types of Cell present in the Stomach?
Parietal Cell: this type of cells Produce hydrochloric acid and several intrinsic factors.
Gastric Chief Cell: They Produce pepsinogen. Chief cells are mainly found in the body of the stomach.
Mucous Cell: They Produce mucin and bicarbonate to create a "neutral zone" to protect the stomach lining from the acid or irritants in the stomach chyme.
G Cell: They Produce the hormone gastrin in response to distention of the stomach mucosa or protein, and stimulate parietal cell production of their secretion.
3. How are digestive enzymes produced in the body? Is there a way to increase these enzymes in one’s body?
Some of your organs like the stomach, pancreas, small intestine, etc., are responsible for the production of digestive enzymes which means that these are created naturally. However, there are ways to consume such enzymes as well. For instance, if an individual is facing problems when it comes to their digestive system, then they may be recommended by a doctor to take certain digestive enzymes in the form of pills or supplements. There is also another way to consume these enzymes and that is by eating more fruits which contain such enzymes. Some of these fruits include bananas, kiwi, avocados, papayas, pineapples, etc.
4. What happens if the level of amylase in your body becomes too much or too less?
Amylase is a digestive enzyme that is responsible for the digestion of carbohydrates. It is secreted by pancreas as well as salivary glands and breaks down starch into simple sugar. However, it is important to maintain the level of amylase in one’s body. This is because increased levels of this digestive enzyme in your body may indicate towards you having inflammation of your pancreas, a damaged duct of the pancreas, or even pancreatic cancer in extreme cases. Whereas low levels of amylase may point out to you having chronic pancreatitis.
5. What is enzyme deficiency?
An enzyme deficiency is mostly a result of a metabolism disorder that has been inherited. Some symptoms of the same are as follows:
Difficulty with feeding and/or swallowing.
Improper muscle coordination.
Brain degeneration.
Slurred speech.
Problems with learning.
Lack or loss of muscle tone.
One of the most common methods of treating such a deficiency is referred to as Enzyme Replacement Therapy or ERT.
6. What are some ways through which one can maintain a healthy digestive system?
Keeping a well maintained and healthy digestive system is extremely vital for various purposes, one of the main being taking good care of your body. Some of the ways through which you can do the same are:
Stay Hydrated. Keep drinking plenty of water everyday as it tends to play a very important role in keeping your body healthy.
Maintain a good and healthy diet. Add high fibre foods to your diet along with probiotics, prebiotics, and lean meats. Also, avoid eating foods with a high fat content.
Avoid skipping meals; try following a regular eating schedule instead.
Cut down the intake of any addictive and harmful habits such as those of drinking too much coffee and/or alcohol, smoking, etc.
Manage stress.
Regular exercise is also helpful.
