Digestive enzymes

DigestionDigestion & &

Digestive Digestive EnzymesEnzymes

Christen Peattie, HHPChristen Peattie, HHP

These exist in the alimentary These exist in the alimentary tracttract

Purpose - breaking down Purpose - breaking down components of food so that components of food so that they can be absorbed by the they can be absorbed by the body. body.

The main sites of action are The main sites of action are the oral cavity, the stomach, the oral cavity, the stomach, the duodenum and the the duodenum and the jejunum. jejunum.

They are secreted by different They are secreted by different glands: the salivary glands, glands: the salivary glands, the glands in the stomach, the the glands in the stomach, the pancreas, and the glands in pancreas, and the glands in the small intestines.the small intestines.

Digestive EnzymesDigestive Enzymes Digestion is the process of Digestion is the process of

making food absorbable by making food absorbable by dissolving it into simpler dissolving it into simpler chemical components. This chemical components. This occurs in the body chiefly occurs in the body chiefly through the action of through the action of digestive enzymes.digestive enzymes.

Enzymes are “molecular machines that do useful work. Some manufacture large, complex molecules for use in the cell. Others take molecules apart, breaking them down into their raw material to be recycled.” - Hari Sharma, MD

Includes the Includes the

Upper and Lower Upper and Lower

Gastrointestinal tractGastrointestinal tract

http://en.wikipedia.org/wiki/Alimentary_tract

AilmentarAilmentary Tracty Tract

The Mouth Starts The Mouth Starts Everything MovingEverything Moving

Even before you eat, when Even before you eat, when you smell a tasty food, see you smell a tasty food, see it, or think about it, it, or think about it, digestion begins.digestion begins.

Saliva begins to form in Saliva begins to form in your mouth. When you do your mouth. When you do eat, the saliva breaks eat, the saliva breaks down the chemicals in the down the chemicals in the food a bit, which helps food a bit, which helps make the food mushy and make the food mushy and easy to swallow. easy to swallow.

Your tongue helps out, Your tongue helps out, pushing the food around pushing the food around while you chew with your while you chew with your teeth.teeth.

When you're ready to When you're ready to swallow, the tongue swallow, the tongue pushes a tiny bit of pushes a tiny bit of masticated food called a masticated food called a bolusbolus toward the back of toward the back of your throat and into the your throat and into the opening of your opening of your esophagus, the second esophagus, the second part of the digestive tract.part of the digestive tract.

#1 Parotid Gland

#2 Submandibular Gland

#3Sublingual Gland

http://en.wikipedia.org/wiki/Salivary_glands

Salivary GlandsSalivary Glands

Oral CavityOral Cavity In the oral cavity, salivary glands secrete ptyalin. In the oral cavity, salivary glands secrete ptyalin. It is a type of amylase, which digests starch into It is a type of amylase, which digests starch into

small segments of multiple sugars and into small segments of multiple sugars and into individual soluble sugars. individual soluble sugars.

Secreted by small and large salivary glands.Secreted by small and large salivary glands. Salivary glands also secrete lysozyme, which kills Salivary glands also secrete lysozyme, which kills

bacteria but is not classified as a digestive enzyme.bacteria but is not classified as a digestive enzyme.

The The esophagusesophagus is like a stretchy pipe that's about 10 inches (25 centimeters) is like a stretchy pipe that's about 10 inches (25 centimeters) long. long.

It moves food from the back of your throat to your stomach. But also at the It moves food from the back of your throat to your stomach. But also at the back of your throat is your windpipe, which allows air to come in and out of your back of your throat is your windpipe, which allows air to come in and out of your body. body.

http://www.plwc.org/oncology_content/content_images/esophagus_credit_large.jpg

The EsophagusThe Esophagus

EsophagusEsophagus When you swallow food or liquids, a special flap called the When you swallow food or liquids, a special flap called the

epiglottisepiglottis covers over the opening of your windpipe to covers over the opening of your windpipe to make sure the food enters the esophagus and not the make sure the food enters the esophagus and not the windpipe.windpipe.

If you've ever drunk something too fast, started to cough, If you've ever drunk something too fast, started to cough, and heard someone say that your drink "went down the and heard someone say that your drink "went down the wrong way," the person meant that it went down your wrong way," the person meant that it went down your windpipe by mistake. This happens when the epiglottis windpipe by mistake. This happens when the epiglottis doesn't have enough time to flop down, and you cough doesn't have enough time to flop down, and you cough involuntarily to clear the windpipe.involuntarily to clear the windpipe.

Once food has entered the esophagus, it doesn't just drop Once food has entered the esophagus, it doesn't just drop right into the stomach. Instead, muscles in the walls of the right into the stomach. Instead, muscles in the walls of the esophagus move in a wavy way (peristaltia) which slowly esophagus move in a wavy way (peristaltia) which slowly squeezes the food through the esophagus. This takes about squeezes the food through the esophagus. This takes about 2 or 3 seconds.2 or 3 seconds.

Your stomach is Your stomach is attached to the end of attached to the end of the esophagus. the esophagus.

It has three important It has three important jobs:to store the food jobs:to store the food you've eaten; break you've eaten; break down the food into a down the food into a liquidy mixture; and liquidy mixture; and slowly empty that slowly empty that mixture into the small mixture into the small intestine.intestine.

StomachStomach

http://www.bupa.co.uk/health_information/images/organ/stomach.gif

StomachStomach The stomach is like a mixer, churning and mashing The stomach is like a mixer, churning and mashing

together all the small balls of food that came down the together all the small balls of food that came down the esophagus into smaller and smaller pieces. It does this esophagus into smaller and smaller pieces. It does this with help from the strong muscles in the walls of the with help from the strong muscles in the walls of the stomach and stomach and gastricgastric juicesjuices that also come from the that also come from the stomach's walls.stomach's walls.

In addition to breaking down food, gastric juices also In addition to breaking down food, gastric juices also help kill bacteria that might be in the eaten food.help kill bacteria that might be in the eaten food.

The enzymes that get secreted in the stomach are The enzymes that get secreted in the stomach are called called gastric enzymesgastric enzymes..

Enzymes in the Enzymes in the StomachStomach

Pepsin is the main gastric Pepsin is the main gastric enzyme. It breaks proteins enzyme. It breaks proteins into small peptide fragments, into small peptide fragments, it is a peptidase.it is a peptidase.

Gelatinase, degrades gelatin Gelatinase, degrades gelatin and collagen, which are the and collagen, which are the proteoglycansproteoglycans found in meat.found in meat.

Gastric amylase degrades Gastric amylase degrades starch, but is of minor starch, but is of minor significance.significance.

Gastric lipase is a tributyrase Gastric lipase is a tributyrase by its biochemical activity, by its biochemical activity, because it acts almost because it acts almost exclusively on tributyrin, a exclusively on tributyrin, a butter fatbutter fat

http://en.wikipedia.org/wiki/Pepsin

Pepsin in complex with pepstatin

PancreasPancreas

http://en.wikipedia.org/wiki/Pancreas

The pancreas is the main The pancreas is the main digestive gland in our body.digestive gland in our body.

It secretes many different It secretes many different enzymes - proteases, enzymes - proteases, nucleases and an amylasenucleases and an amylase

Pancreatic enzymesPancreatic enzymes Trypsin, is a peptidase, like pepsin in the stomach.Trypsin, is a peptidase, like pepsin in the stomach. Chymotrysin, is also a peptidase.Chymotrysin, is also a peptidase. Steapsin, is a carbohydrate digesting enzyme.Steapsin, is a carbohydrate digesting enzyme. Carboxypeptidase splits peptide fragments into individual Carboxypeptidase splits peptide fragments into individual

amino acids. It is a protease.amino acids. It is a protease. Several elastases degrade the protein elastin and other Several elastases degrade the protein elastin and other

proteins.proteins. Several nucleases degrade nucleic acids, like DNAase and Several nucleases degrade nucleic acids, like DNAase and

RNAase.RNAase. Pancreatic amylase, besides starch and glycogen, degrades Pancreatic amylase, besides starch and glycogen, degrades

also most other hydrocarbons, but not cellulose . Forming also most other hydrocarbons, but not cellulose . Forming disaccharides and trisaccharides.disaccharides and trisaccharides.

Bile from the Liver, emulsifies fat, allowing more efficient Bile from the Liver, emulsifies fat, allowing more efficient use of the lipase enzyme in the duodenum. This converts use of the lipase enzyme in the duodenum. This converts lipids to their component fatty acid and glycerol molecules.lipids to their component fatty acid and glycerol molecules.

The Small IntestineThe Small Intestine The small intestine is a long tube that's about 1 1/2 inches to 2 inches The small intestine is a long tube that's about 1 1/2 inches to 2 inches

(about 3.5 to 5 centimeters) around, and it's packed inside you beneath (about 3.5 to 5 centimeters) around, and it's packed inside you beneath your stomach. If you stretched out an adult's small intestine, it would be your stomach. If you stretched out an adult's small intestine, it would be about 22 feet long (6.7 meters).about 22 feet long (6.7 meters).

The small intestine breaks down the food mixture even more so your body The small intestine breaks down the food mixture even more so your body can absorb all the vitamins, minerals, proteins, carbohydrates, and fats can absorb all the vitamins, minerals, proteins, carbohydrates, and fats from your food. The small intestine can help extract them - with a little from your food. The small intestine can help extract them - with a little help from the pancreas, liver, and gallbladder.help from the pancreas, liver, and gallbladder.

These organs send different juices to the first part of the small intestine. These organs send different juices to the first part of the small intestine. The juices help to digest food and allow the body to absorb nutrients. The The juices help to digest food and allow the body to absorb nutrients. The pancreas makes juices that help the body digest fats and protein. - pancreas makes juices that help the body digest fats and protein. - pancreatic enzymes. pancreatic enzymes.

Your food may spend as long as 4 hours in the small intestine and will Your food may spend as long as 4 hours in the small intestine and will become a very thin, watery mixture. The nutrients from food can pass from become a very thin, watery mixture. The nutrients from food can pass from the small intestine into the blood stream. the small intestine into the blood stream.

Once in the blood, your body is closer to benefiting from complex Once in the blood, your body is closer to benefiting from complex carbohydrates, vitamins, proteins, and minerals. The next stage in carbohydrates, vitamins, proteins, and minerals. The next stage in digestion is the liver. And the leftover waste - remnants of the food that digestion is the liver. And the leftover waste - remnants of the food that your body can't use - goes on to the large intestine.your body can't use - goes on to the large intestine.

Small IntestineSmall Intestine

The jejunum and ileum secretes a juice called succus The jejunum and ileum secretes a juice called succus entericusentericus which contains six types of enzymes that degrade which contains six types of enzymes that degrade disaccharides into monosaccarides - these are considered disaccharides into monosaccarides - these are considered peptidases.peptidases.

http://en.wikipedia.org/wiki/Jejunum

Peptidases - enzymesPeptidases - enzymes

Sucrase, breaks down sucrose Sucrase, breaks down sucrose into glucose and fructoseinto glucose and fructose

Maltase, breaks down maltose Maltase, breaks down maltose into glucose.into glucose.

Isomaltase, breaks down maltose Isomaltase, breaks down maltose and isomaltose and isomaltose

Lactase, breaks down lactose into Lactase, breaks down lactose into glucose and galactose glucose and galactose

Intestinal lipase, breaks down Intestinal lipase, breaks down fatty acidsfatty acids

Erepsin, is a protein-digesting Erepsin, is a protein-digesting enzymeenzyme

Sucrose, a common disaccharide

http://en.wikipedia.org/wiki/Digestive_enzyme

http://www.britishlivertrust.org.uk/content/liver/images/liver-biliarytract.gif

Liver and GallbladderLiver and Gallbladder Nutrient-rich blood comes Nutrient-rich blood comes

directly to the liver for directly to the liver for processing.processing.

A juice from the liver called A juice from the liver called bile helps to absorb fats into bile helps to absorb fats into the bloodstream. the bloodstream.

The liver filters out harmful The liver filters out harmful substances or wastes, turning substances or wastes, turning some of the waste into more some of the waste into more bile.bile.

The liver even helps figure out The liver even helps figure out how many nutrients will go to how many nutrients will go to the rest of the body, and how the rest of the body, and how many will stay behind in many will stay behind in storage. For example, the storage. For example, the liver stores certain vitamins liver stores certain vitamins and a type of sugar your body and a type of sugar your body uses for energy.uses for energy.

The gallbladder serves as a The gallbladder serves as a warehouse for bile, storing it warehouse for bile, storing it until the body needs it.until the body needs it.

Large IntestineLarge Intestine At 3 or 4 inches around (about 7 At 3 or 4 inches around (about 7

to 10 centimeters), the large to 10 centimeters), the large intestine is fatter than the small intestine is fatter than the small intestine and it's almost the last intestine and it's almost the last stop on the digestive tract. Like stop on the digestive tract. Like the small intestine, it is packed the small intestine, it is packed into the body, and would measure into the body, and would measure 5 feet (about 1.5 meters) long if 5 feet (about 1.5 meters) long if you spread it out.you spread it out.

The large intestine has a tiny tube The large intestine has a tiny tube with a closed end coming off it with a closed end coming off it called the appendix. It's part of called the appendix. It's part of the digestive tract, but it doesn't the digestive tract, but it doesn't seem to do anything, though it seem to do anything, though it can cause big problems, because can cause big problems, because it sometimes gets infected and it sometimes gets infected and needs to be removed. needs to be removed.

The large intestine, or colon, may The large intestine, or colon, may be divided into the cecum, be divided into the cecum, ascending colon, transverse ascending colon, transverse colon, descending colon, and colon, descending colon, and sigmoid colon.sigmoid colon.

http://www.becomehealthynow.com/popups/lrg_intest.htm

Digestive WasteDigestive Waste

After most of the nutrients are removed from the digested After most of the nutrients are removed from the digested food, there is waste left over - stuff your body can't use. food, there is waste left over - stuff your body can't use. This becomes feces. This becomes feces.

This passes through the part of the large intestine called This passes through the part of the large intestine called the colon - which is where the body gets its last chance to the colon - which is where the body gets its last chance to absorb the water and some minerals into the blood. absorb the water and some minerals into the blood.

As the water leaves the waste product, what's left gets As the water leaves the waste product, what's left gets harder and harder as it keeps moving along, until it harder and harder as it keeps moving along, until it becomes a solid. becomes a solid.

The large intestine pushes the feces into the rectum, the The large intestine pushes the feces into the rectum, the very last stop on the digestive tract. The solid waste stays very last stop on the digestive tract. The solid waste stays here until the body is ready to make a bowel movement- here until the body is ready to make a bowel movement- pushing it through the anuspushing it through the anus

A Healthy Digestive A Healthy Digestive SystemSystem

You can help your digestive system by drinking plenty You can help your digestive system by drinking plenty of water and eating a healthy diet that includes of water and eating a healthy diet that includes organic, fresh foods rich in fiber. organic, fresh foods rich in fiber.

High-fiber foods, like fruits, vegetables, and whole High-fiber foods, like fruits, vegetables, and whole grains, make it easier for digested food to pass grains, make it easier for digested food to pass through your system and keeps your colon healthy. through your system and keeps your colon healthy.

The digestive system is a very important part of your The digestive system is a very important part of your body. Without it, you couldn't get the nutrients you body. Without it, you couldn't get the nutrients you need to grow and repair properly or stay youthful and need to grow and repair properly or stay youthful and healthy. healthy.

ResourcesResourceshttp://www.kidshealth.org

http://en.wikipedia.org

http://www.bupa.co.uk

http://www.plwc.org

http://www.becomehealthynow.com

http://www.britishlivertrust.org

Freedom from Disease; Hari Sharma; Veda Publishing; Toronto; 1993.

Merriam Webster’s Medical Desk Dictionary; Merriam- Webster Inc.; Springfield, MA; 1993.