
Enzymes and Their Role in Digestion
Digestive enzymes are manufactured within our body to digest our carbohydrates, proteins and fats in our food. There are about 22 enzymes in the body that work to digest our food. Digestive enzymes are secreted by salivary gland , stomach , pancreas, and the small intestine. Technically, digestive enzymes are also considered to be metabolic enzymes, whose metabolic role is to transform undigested foods into nutrients. However, digestive enzymes can also be supplemented from an outside source, in the form of raw food or enzyme supplements.
The enzymes in your body aid in the completion of critical tasks. Building muscle, eliminating poisons, and breaking down food particles are just a few of them. Good digestion is one of the foundations of good health. Without enzymes, proper digestion cannot occur, our cells would not receive adequate nutrition and the body would begin to completely shut down.
The Working of Enzymes in the Digestive System
The importance of proper digestion is mind boggling. Every function must be perfectly synchronized with every other function. When we lack a particular enzyme, vitamin, or mineral, the resulting imbalance causes disease. If you have digestive problems, you will have trouble rebuilding cells, which leads to an array of health disorders. You may think it is too simplistic to conclude that illness is caused by inadequate digesiton, but we are here to convinced that it is true.
Let us now begin our journey on how enzymes work in your digestive system !
The Mouth
Food is mechanically digested here by cutting, chewing and grinding of teeth. Saliva as a lubrication is added – this contains amylase to begin the digestion of starch. This enzyme begins to breakdown carbohydrate of our meals such as potatoes and pasta into smaller sugars like maltose .
Oesophagus
Boluses ( balls ) of food pass through by the peristalsis process , which is from mouth to stomach.
Stomach
Muscular walls squeeze on food to make it semi-liquid. Gastric juice contains protease to digest protein and hydrochloric acid ( HCl ) to maintain an optimum pH ( 1-2,5 ). The stomach ( gastric ) area is extremely acidic , so the enzyme that works here must be acid stable. Inside our stomach, gastric protease begins to break the protein component of our foods, either from animal or vegetable sources, into smaller pieces, and gastric lipase starts to break down fats.
Duodenum
This is the first part of the small intestines which receives pancreatic juice containing protease, lipase and amylase. The juice also contains sodium hydrogen carbonate, which neutralises acid from the stomach, producing a pH value of 7-8.
Pancreatic amylase: Chops starch molecules and carbohydrate prevalend in potatoes, vegetables and many snack food molecules to simpleast sugars and carbohydrates into maltose.
Lipases : Lipases function in the digestion of fats, oils, and fat-soluble vitamins that are found in most dairy products, nuts, oils, and meat.
Proteases : It is responsible for breaking down proteins that are found in meats, nuts, eggs and cheese into smaller amino acids. Proteases are also responsible for keeping the small intestine free from parasites ( intestinal worm, yeast overgrowth and bacteria ). A lack of proteases can cause incomplete digestion that can lead to allergies and the formation of toxins.
Pancrease
Secretes pancreatic juice into the duodenum, also makes the hormones insulin and glucagon.
Liver
Makes bile, which was stored on the gall bladder. Bile contains salts that emulsify fats, forming droplets with a large surface area to make digestion by lipase more efficient. Digested foods are assimilated here. For example, glucose is stored as glycogen , surplus amino acids are deaminated.
The Ileum
The second part of the small intestine. Enzymes in the epithelial lining breakdown lactose and peptides. It’s surface area is increased by the presence of villi which allow the efficient absorption of digestion food molecules. Bile is also absorbed here and returns to the liver through blood vessels in the intestinal walls.
Rectum
Here, it stores faeces until it is egested.
Anus
It has muscles to control when faeces is egested from the body.
This is how things happen, in a healthy human digestive system from the mouth to the large intestines. No burping, no heartburn, no acid reflux, no cramping, no bloating, no gas ! Just smooth sailing down the thirty-foot- long tube of our gastrointestinal tract. To make it easy and accurate to understand, let’s look at the table prepared below :
Summary of the Digestive Enzymes
Site of Enzyme Origin |
Enzyme |
Nutrient it breaks down |
Product of Enzyme Action |
Place of Enzyme Action |
Salivary Glands |
Salivary Amylase |
Carbohydrates- sugar |
Maltase |
Mouth |
Gastric Glands |
Pepsin |
Proteins |
Amino Acids |
Stomach |
Liver |
Bile |
Fats/Lipids |
Emulsify Fats |
Small Intestine |
Small Intestine |
Maltase, Lactase, Sucrase |
Carbohydrate Sugar |
-Glucose -Glucose & Galactose -Glucose & Fructose |
Small Intestine |
Pancreas |
Trypsin, Lipase, Amylase |
Proteins, Fats/Lipids, Carbohydrates |
Amino acids, Glycerol/ Fatty Acids, Maltose |
Small Intestine |
References
[1] Stacy Sampson D.O. James Roland. ( Jan 16, 2019 ). Why are enzymes important ? Retrieved from healthline : https://www.healthline.com/health/why-are-enzymes-important
[2] Barbara Bolen,PhD. Robert Burakoff,MD. ( Sep 8, 2020 ). Types and Functions of Digestive Enzymes. Retrieved from verywell health : https://www.verywellhealth.com/what-are-digestive-enzymes-1945036
[3]Saurabh Sethi MD. Ann Pietrangelo. ( Feb 28, 2020 ). The role of digestive enzymes in gastrointerstinal disorders. Retrieved from healthline: https://www.healthline.com/health/exocrine-pancreatic-insufficiency/the-role-of-digestive-enzymes-in-gi-disorders
[4] Elaine K MD. Tim Newman. ( Jan 11, 2018 ). Enzymes: How they work and what they do? . Retrieved from Medical News Today : https://www.medicalnewstoday.com/articles/319704
[5]Katherine Marengo LDN. Rachel Nall MSN. ( Sep 5, 2018 ). Understanding Chemical Digesiton. Retrieved from healthline: https://www.healthline.com/health/chemical-digestion