Digestive Enzymes
Why do we have to know about digestive enzymes? This is a question that most people would not mind to bother searching for the answer. This article will attempt to explain in a very simple language that everyone can understand how important these enzymes in healthy digestion. It may sound scientifically boring topic to discuss, but rest assured that once you become acquainted with each digestive enzymes, you will appreciate them as much as you appreciate your life.
What are digestive enzymes?
Before we understand how enzymes aid in digestion, let us know first what the definition of enzymes is, where they came from and how they function?
First and foremost, enzymes are produced by our bodies that either metabolic, digestive, or can be found in food that we eat. Majority of the enzymes are systematic and can produce enzymes if these are required and needed. According to nutrition experts, enzyme potential can be depleted and lost about 13% for every ten years of existence. So, the more we get older, the more our enzyme potential becomes exhausted.
In digestion, enzymes are found and produced inside our digestive tract including the mouth, stomach, pancreas, and small intestine.
Like a catalyst that brings about change, enzymes as complex protein act the same way which control the biochemical reactions and speed up the rate without even changing or altering the nature or the direction of the reaction, under the mild conditions of temperature, pH, and cellular concentrations. Enzymes are vital to all living organisms making it easier for chemical reactions to occur and sustain life.
Main Functions of Digestive Enzymes
Stimulate all functions of the body and helps to produce neurotransmitters which allow our nervous system to work properly.
Transporter of elements in the body. Purify the blood, build muscle, and deliver hormones.
Break down food substances into simple sugars, fatty acids, and amino acids and facilitate chemical reactions that allow metabolism to happen.
Get rid of unwanted chemicals and remove toxic substances.
POINTS TO REMEMBER: Generally, in naming enzymes, the name of the substance, for example protein becomes protease, adding “-ase” at the end of the substance on which the enzyme acts. There are approximately 3,000 enzymes in our body but only 22 of which are found in digestive system.
There are three enzyme groups responsible in breaking down foods: the proteolytic enzymes or proteases; it break down the 20 amino acids that are composed of protein and each protease targets different amino acids; the amylolytic enzymes or amylases break down different sugars like fruit sugars, milk sugar, and sucrose; lastly, lipolytic enzymes or lipases decompose fats including oils.
Mouth
It is part of the process of digestion that all food substances must be broken before they can be absorbed. Starts in the mouth, when food is chewed, the salivary glands secrete ptyalin or amylase enzymes which help to break down the starch into multiple sugars secreted by salivary glands. Also, salivary glands secrete bromelaine like same enzyme found in pineapple acts as anti-inflammatory agent, and lysozyme that kills bacteria. Take note that the latter enzyme, the lysozyme is not classified as part of the digestive enzyme.
Stomach
As food moves into the stomach, gastric juices that is acid juice with main components of hydrochloric acid, pepsinogen, gelatinase, gastric amylase and gastric lipase.
Hydrochloric acid dissolves food and kills microorganisms, while pepsinogen or protein breaking enzymes are secreted by parietal glands help to chop up protein molecules into much smaller sub-components. The working combination of hydrochloric acid, together with pepsin, can break down proteins into their individual amino acids. Since HCI is a very strong acid, it kills microorganisms present in the food and converts pepsinogen into pepsin.
Gastric enzymes are what we called enzymes secreted in the stomach. Here are the following gastric enzymes:
Pepsin
It is found in gastric juice and produced by the walls of the stomach occurs as white to yellow brown powders or yellowish brown to brown liquids. It is responsible to break down proteins into peptide fragments called polypeptides. It depends on the acidic environment of the stomach where most of its works done.
During digestion, it links amino acids to breaking down of dietary proteins to their components. However, it only split proteins at certain points so these are not digested entirely to the amino acid stage. How is that possible to happen? The food has to move into the intestines in which enzymes complete the process of digestion.
In order for pepsin to function well, it requires low pH level and taking antacid may hinder pepsin to work.
Gelatinase
From the root word “gelatin” and most of us will think that it is the edible jelly that we usually eat as a dessert. If you may ask where it came from, it is obtained from animal tissues particularly in bone and skin. In chemistry and biology, it is a proteolytic enzyme which allows hydrolysing gelatin into sub-compounds like polypeptides, peptides, and amino acids.
Gastric Amylase
This is an enzyme which changes complex sugars or carbohydrates into simple sugar or maltose during digestion. It is also another type of protein that found in salivary glands. Can you imagine if the stomach environment is acidic, what happened to the amylase when food is already in the stomach? Since we talk about hydrochloric acid awhile ago, its acid will denature or deactivated the amylase once the swallowed food enters the stomach. We have to understand that the salivary amylase works well with pH level of 7, and vice versa. Gastric amylase cannot function longer to break down starch and glycogen, the way it should be, due to gastric juices that drops the pH level. On the other hand, before pH level drops below 7, starches are partially broken down.
Gastric Lipase
An acid lipase with a pH of 3-6 and found in the mucosa in the stomach or the stomach lining. Its main function is to digest oils, fats and fat-soluble vitamins. It is very essential for infant digestion since the gastric acid pH of infant is much less than the adult, therefore, gastric lipase cannot function well in an acidic environment.
Rennin Enzymes
It is produced by the stomach of young mammals in which main function is to solidify milk. It is worth to take note that only pepsin and rennin are the two enzymes produced in the stomach. Here is what happens when milk enters our stomach: the prorennin is stimulated by hydrochloric acid and converts the milk into active rennin enzyme. It curdles the milk separating it into semi-solid curds and whey. Why is it necessary? It is essential if the milk stays longer in the stomach so that milk proteins can be digested properly.
Pancreas
To refresh our readers, pancreas is the digestive organ found in the abdomen over the spine. Stomach is only under the pancreas and has two important functions: insulin production and pancreatic enzyme production for digestion and food absorption. It secretes lipases responsible to break down fats and oils into fatty acids so it can be absorbed by the body, proteases are for protein digestion and keep the intestine from parasites like yeast, protozoa and bacteria, and amylases which digest starch molecules into maltose and found in salivary glands. Another, the trypsin and chymotrypsin are working to digest proteins to peptides.
How important those enzymes? Pancreatic enzymes are indeed very important in balancing physiology and lessening the risk of cancer. There are several studies showed that cancer cells cannot survive in the presence of pancreatic enzymes. In 1905, a pancreatic enzyme was injected into mice tumors and the findings of Beard, the researcher, were released at the Biological Society of Liverpool, linking pancreatic enzymes and cancer. Although the statement was disputed by many of his colleagues, he strongly justified his claims when he published in 1975 his studies confirming the pancreatic enzymes that were injected to cancer patients can enter the blood stream and recycled back to the pancreas. Furthermore, he verified how oral enzymes can prevent cancer from attacking organs and tissues by ingestion.
Precaution: Oral pancreatic enzymes should not be taken by people who are undergoing therapies in the stomach because it can degrade anti-neoplastin peptides. It is best taken with the recommendation and prescription of doctors.
Small Intestine
The juice secreted by jejunum and ileum of the stomach is called succus entericus. There are four types of enzymes that degrade disaccharides into monosaccharide: the sucrase, maltase, isomaltase, and peptidases.
Sucrase
It is a yeast-derived enzyme that splits sucrose or complex sugar (refined sugar) into glucose or simple sugar and fructose (fruit sugar). It is beneficial for immune system and for muscle mass.
Maltase
The function of maltase is to catalyze the hydrolysis (chemical reaction with water) of the disaccharide maltose (white crystalline sugar). During digestion, starch is partially transformed into maltose with the help of amylase enzymes, then maltase is secreted by the small intestine and then converts it into glucose and either our body utilizes it or stores it in the liver as glycogen or animal starch. It has the capacity to break the bond of two glucose pieces.
There is a genetically disease like Acid maltase deficiency or AMD wherein patients have defect in a gene called acid alpha-glucosidase or GAA causes glycogen (starch used to store short-term energy) to build up in muscles. Therefore, patients with AMD have limited ability to produce acid maltase which is required in order to process excess glycogen in the muscle cells and leads to weakening of the muscles in respiratory system and heart.
Isomaltase
It is an enzyme that split the bonds connecting saccharides or the sweet-tasting carbohydrates that cannot be broken down by maltase or amylase.
There is also sucrase-isomaltase deficiency that greatly affects the ability to digest certain sugars like maltose (sugars in grains) and sucrose (sugars in fruits). This ailment becomes more apparent in infant who experience diarrhea, stomach cramps, and bloating after started to consume grains, juices, and fruits.
Peptidases
Peptidase catalyzes the hydrolysis of peptides (synthetic compounds of 2 or more linked amino acids) into amino acids. Peptidases and proteases are essential in protein activation to modulate blood clotting and activate the immune system.
Lactase
It is found in the lining of the gut, the alimentary canal from the stomach to the anus. It degrades the lactose which is the content of milk. That is why people who have no enough lactase in their body have this lactose intolerance wherein the lactose is hard to digest. People experience the symptoms of bloating, diarrhea and abdominal pain because the lactose is utilized by bacteria to form gas.
Conclusion
Many people do not realize how vital these enzymes to our holistic health because they are solely responsible in every chemical reaction in our body so that our organs and systems can function well. Enzymes in food that we eat are only found in uncooked and unprocessed foods; therefore you can imagine how we kill those important enzymes by cooking.
Although, it is true that our body organs like pancreas can produce its own enzymes so we do not have to worry too much if we are not getting enough enzymes in food we consume. However, it is worth to remember that our body has limitation to produce good quality enzymes and these are depleted as we grow older. Forcing the pancreas to produce substantial amounts of enzymes loses it ability to produce superior enzymes and the metabolic system is gradually affected along with it. Thus, aging process and many deficiencies we experience are the end results of body toxins that our body has to deal with the help of enzymes.
Now, the question how important these digestive enzymes to our survival can be answered in simplified well explained statement of Dr. Edward Howell in his book Enzyme Nutrition that our length of life is in equal proportion to the rate of exhaustion of the enzyme potential of all living organisms.
