Because the liver has low levels of transaminases for these amino acids, it cannot oxidize them to a significant extent and they enter the systemic circulation. The branched chain amino acids are taken up slowly by skeletal muscle and other tissues.

These peripheral non-hepatic tissues utilize the amino acids derived from the diet principally for net protein synthesis. Digestive proteases are synthesized as larger, inactive forms zymogens , which, after secretion, are cleaved to produce active proteases.

The amino acids indicated after the curly brace in the diagram below are the preferred amino acids at which each of the indicated enzymes cleaves. In the stomach, pepsin begins the digestion of dietary proteins by hydrolyzing them to smaller polypeptides.

Pepsinogen is secreted by chief cells of the stomach, parietal cells secrete HCl. The acid environment alters the conformation of pepsinogen so that it can cleave itself to yield pepsin. Pepsin acts as an endopeptidase to cleave dietary proteins with a broad spectrum of specificity, although it prefers to cleave peptide bonds in which the carboxyl group is provided by aromatic or acidic amino acids.

The products are smaller peptides and some free amino acids In the intestine, bicarbonate neutralizes stomach acid, and the pancreas secretes several inactive proenzymes zymogens , which, when activated, collectively digest peptides to single amino acids. As with other macronutrients, the liver is the checkpoint for amino acid distribution and any further breakdown of amino acids, which is very minimal.

Assuming the body has enough glucose and other sources of energy, those amino acids will be used in one of the following ways:. If there is not enough glucose or energy available, amino acids can also be used in one of these ways:.

In order to use amino acids to make ATP, glucose, or fat, the nitrogen first has to be removed in a process called deamination , which occurs in the liver and kidneys. The nitrogen is initially released as ammonia, and because ammonia is toxic, the liver transforms it into urea.

Urea is then transported to the kidneys and excreted in the urine. Urea is a molecule that contains two nitrogens and is highly soluble in water. This makes it ideal for transporting excess nitrogen out of the body. Because amino acids are building blocks that the body reserves in order to synthesize other proteins, more than 90 percent of the protein ingested does not get broken down further than the amino acid monomers.

definition An acid that is a component of gastric juices; creates an acidic environment in the stomach, killing bacteria and aiding in protein digestion. When the three-dimensional structure of a protein is unfolded due to a change in the environment e. An enzyme made by the pancreas; facilitates the chemical breakdown of proteins in the small intestine.

An enzyme that facilitates the chemical breakdown of protein in the small intestine; activates other protein-digesting enzymes.

A process that removes nitrogen from amino acids before they are used to synthesize ATP, glucose, or fat. Nutrition: Science and Everyday Application, v. Protein digestion in the human GI tract. Protein digestion in the stomach Because of the hydrochloric acid in the stomach, it has a very low pH of 1.

What happens to absorbed amino acids? Assuming the body has enough glucose and other sources of energy, those amino acids will be used in one of the following ways: Protein synthesis in cells around the body Making nonessential amino acids needed for protein synthesis Making other nitrogen-containing compounds Rearranged and stored as fat there is no storage form of protein If there is not enough glucose or energy available, amino acids can also be used in one of these ways: Rearranged into glucose for fuel for the brain and red blood cells Metabolized as fuel, for an immediate source of ATP In order to use amino acids to make ATP, glucose, or fat, the nitrogen first has to be removed in a process called deamination , which occurs in the liver and kidneys.

An enzyme found in gastric juices; aids in the chemical breakdown of proteins. Enzymes that aid in the chemical breakdown of proteins in the small intestine. Liver cells combine the remaining chylomicron remnants with proteins, forming lipoproteins that transport cholesterol in the blood.

Figure 6. Unlike amino acids and simple sugars, lipids are transformed as they are absorbed through epithelial cells. The products of nucleic acid digestion—pentose sugars, nitrogenous bases, and phosphate ions—are transported by carriers across the villus epithelium via active transport. These products then enter the bloodstream.

The electrolytes absorbed by the small intestine are from both GI secretions and ingested foods. Since electrolytes dissociate into ions in water, most are absorbed via active transport throughout the entire small intestine.

During absorption, co-transport mechanisms result in the accumulation of sodium ions inside the cells, whereas anti-port mechanisms reduce the potassium ion concentration inside the cells. To restore the sodium-potassium gradient across the cell membrane, a sodium-potassium pump requiring ATP pumps sodium out and potassium in.

In general, all minerals that enter the intestine are absorbed, whether you need them or not. Iron —The ionic iron needed for the production of hemoglobin is absorbed into mucosal cells via active transport.

Once inside mucosal cells, ionic iron binds to the protein ferritin, creating iron-ferritin complexes that store iron until needed.

When the body has enough iron, most of the stored iron is lost when worn-out epithelial cells slough off. When the body needs iron because, for example, it is lost during acute or chronic bleeding, there is increased uptake of iron from the intestine and accelerated release of iron into the bloodstream.

Since women experience significant iron loss during menstruation, they have around four times as many iron transport proteins in their intestinal epithelial cells as do men.

Calcium —Blood levels of ionic calcium determine the absorption of dietary calcium. When blood levels of ionic calcium drop, parathyroid hormone PTH secreted by the parathyroid glands stimulates the release of calcium ions from bone matrices and increases the reabsorption of calcium by the kidneys.

PTH also upregulates the activation of vitamin D in the kidney, which then facilitates intestinal calcium ion absorption. The small intestine absorbs the vitamins that occur naturally in food and supplements.

Fat-soluble vitamins A, D, E, and K are absorbed along with dietary lipids in micelles via simple diffusion. This is why you are advised to eat some fatty foods when you take fat-soluble vitamin supplements.

Most water-soluble vitamins including most B vitamins and vitamin C also are absorbed by simple diffusion. An exception is vitamin B 12 , which is a very large molecule.

Intrinsic factor secreted in the stomach binds to vitamin B 12 , preventing its digestion and creating a complex that binds to mucosal receptors in the terminal ileum, where it is taken up by endocytosis.

Each day, about nine liters of fluid enter the small intestine. About 2. About 90 percent of this water is absorbed in the small intestine. Water absorption is driven by the concentration gradient of the water: The concentration of water is higher in chyme than it is in epithelial cells.

Thus, water moves down its concentration gradient from the chyme into cells. As noted earlier, much of the remaining water is then absorbed in the colon.

The small intestine is the site of most chemical digestion and almost all absorption. Chemical digestion breaks large food molecules down into their chemical building blocks, which can then be absorbed through the intestinal wall and into the general circulation.

Intestinal brush border enzymes and pancreatic enzymes are responsible for the majority of chemical digestion. The breakdown of fat also requires bile. Most nutrients are absorbed by transport mechanisms at the apical surface of enterocytes.

Exceptions include lipids, fat-soluble vitamins, and most water-soluble vitamins. With the help of bile salts and lecithin, the dietary fats are emulsified to form micelles, which can carry the fat particles to the surface of the enterocytes.

There, the micelles release their fats to diffuse across the cell membrane. The fats are then reassembled into triglycerides and mixed with other lipids and proteins into chylomicrons that can pass into lacteals. Other absorbed monomers travel from blood capillaries in the villus to the hepatic portal vein and then to the liver.

chylomicron: large lipid-transport compound made up of triglycerides, phospholipids, cholesterol, and proteins. lactase: brush border enzyme that breaks down lactose into glucose and galactose.

lipoprotein lipase: enzyme that breaks down triglycerides in chylomicrons into fatty acids and monoglycerides. maltase: brush border enzyme that breaks down maltose and maltotriose into two and three molecules of glucose, respectively.

micelle: tiny lipid-transport compound composed of bile salts and phospholipids with a fatty acid and monoacylglyceride core. pancreatic amylase: enzyme secreted by the pancreas that completes the chemical digestion of carbohydrates in the small intestine.

pancreatic lipase: enzyme secreted by the pancreas that participates in lipid digestion. pancreatic nuclease: enzyme secreted by the pancreas that participates in nucleic acid digestion. Skip to main content.

Module 7: The Digestive System. Search for:.

The two major pancreatic enzymes that digest proteins are trypsin and chymotrypsin. Amino acids, dipeptides, and tripeptides are absorbed into the cells of the intestinal wall. The cells that line the small intestine release peptidases enzymes that break down dipeptides and tripeptides into single amino acids.

The muscle contractions of the small intestine mix and propel the amino acids to the absorption sites. Once the amino acids are in the blood, they are transported to the liver.

As with other macronutrients, the liver is the checkpoint for amino acid distribution and any further breakdown of amino acids, which is very minimal. Recall that amino acids contain nitrogen, so further breakdown of amino acids releases nitrogen-containing ammonia.

Because ammonia is toxic, the liver transforms it into urea, which is then transported to the kidney and excreted in the urine. Because amino acids are building blocks that the body reserves in order to synthesize other proteins, more than 90 percent of the protein ingested does not get broken down further than the amino acid monomers.

Just as some plastics can be recycled to make new products, amino acids are recycled to make new proteins. All cells in the body continually break down proteins and build new ones, a process referred to as protein turnover.

Amino acids are used not only to build proteins, but also to build other biological molecules containing nitrogen, such as DNA and RNA, and to some extent to produce energy.

It is critical to maintain amino acid levels within this cellular pool by consuming high-quality proteins in the diet, or the amino acids needed for building new proteins will be obtained by increasing protein destruction from other tissues within the body, especially muscle.

This amino acid pool is less than one percent of total body-protein content. Thus, the body does not store protein as it does with carbohydrates as glycogen in the muscles and liver and lipids as triglycerides in adipose tissue.

Search site Search Search. Go back to previous article. Sign in. Learning Objectives Discuss how proteins are digested and absorbed by our bodies.

This results in molecules small enough to enter the bloodstream. Figure 3. The digestion of protein begins in the stomach and is completed in the small intestine. Figure 4. Proteins are successively broken down into their amino acid components. A healthy diet limits lipid intake to 35 percent of total calorie intake.

The most common dietary lipids are triglycerides, which are made up of a glycerol molecule bound to three fatty acid chains. Small amounts of dietary cholesterol and phospholipids are also consumed. The three lipases responsible for lipid digestion are lingual lipase, gastric lipase, and pancreatic lipase.

However, because the pancreas is the only consequential source of lipase, virtually all lipid digestion occurs in the small intestine. Pancreatic lipase breaks down each triglyceride into two free fatty acids and a monoglyceride. The fatty acids include both short-chain less than 10 to 12 carbons and long-chain fatty acids.

The nucleic acids DNA and RNA are found in most of the foods you eat. Two types of pancreatic nuclease are responsible for their digestion: deoxyribonuclease , which digests DNA, and ribonuclease , which digests RNA.

The nucleotides produced by this digestion are further broken down by two intestinal brush border enzymes nucleosidase and phosphatase into pentoses, phosphates, and nitrogenous bases, which can be absorbed through the alimentary canal wall. The large food molecules that must be broken down into subunits are summarized in Table 2.

The mechanical and digestive processes have one goal: to convert food into molecules small enough to be absorbed by the epithelial cells of the intestinal villi. The absorptive capacity of the alimentary canal is almost endless.

Each day, the alimentary canal processes up to 10 liters of food, liquids, and GI secretions, yet less than one liter enters the large intestine.

Almost all ingested food, 80 percent of electrolytes, and 90 percent of water are absorbed in the small intestine. Although the entire small intestine is involved in the absorption of water and lipids, most absorption of carbohydrates and proteins occurs in the jejunum.

Notably, bile salts and vitamin B 12 are absorbed in the terminal ileum. By the time chyme passes from the ileum into the large intestine, it is essentially indigestible food residue mainly plant fibers like cellulose , some water, and millions of bacteria.

Figure 5. Absorption is a complex process, in which nutrients from digested food are harvested. Absorption can occur through five mechanisms: 1 active transport, 2 passive diffusion, 3 facilitated diffusion, 4 co-transport or secondary active transport , and 5 endocytosis.

As you will recall from Chapter 3, active transport refers to the movement of a substance across a cell membrane going from an area of lower concentration to an area of higher concentration up the concentration gradient.

Passive diffusion refers to the movement of substances from an area of higher concentration to an area of lower concentration, while facilitated diffusion refers to the movement of substances from an area of higher to an area of lower concentration using a carrier protein in the cell membrane.

Co-transport uses the movement of one molecule through the membrane from higher to lower concentration to power the movement of another from lower to higher. Finally, endocytosis is a transportation process in which the cell membrane engulfs material.

It requires energy, generally in the form of ATP. Moreover, substances cannot pass between the epithelial cells of the intestinal mucosa because these cells are bound together by tight junctions. Thus, substances can only enter blood capillaries by passing through the apical surfaces of epithelial cells and into the interstitial fluid.

Water-soluble nutrients enter the capillary blood in the villi and travel to the liver via the hepatic portal vein. In contrast to the water-soluble nutrients, lipid-soluble nutrients can diffuse through the plasma membrane.

Once inside the cell, they are packaged for transport via the base of the cell and then enter the lacteals of the villi to be transported by lymphatic vessels to the systemic circulation via the thoracic duct.

The absorption of most nutrients through the mucosa of the intestinal villi requires active transport fueled by ATP.

The routes of absorption for each food category are summarized in Table 3. All carbohydrates are absorbed in the form of monosaccharides.

The small intestine is highly efficient at this, absorbing monosaccharides at an estimated rate of grams per hour. All normally digested dietary carbohydrates are absorbed; indigestible fibers are eliminated in the feces. The monosaccharides glucose and galactose are transported into the epithelial cells by common protein carriers via secondary active transport that is, co-transport with sodium ions.

The monosaccharides leave these cells via facilitated diffusion and enter the capillaries through intercellular clefts. The monosaccharide fructose which is in fruit is absorbed and transported by facilitated diffusion alone.

The monosaccharides combine with the transport proteins immediately after the disaccharides are broken down. Active transport mechanisms, primarily in the duodenum and jejunum, absorb most proteins as their breakdown products, amino acids.

Almost all 95 to 98 percent protein is digested and absorbed in the small intestine. The type of carrier that transports an amino acid varies. Most carriers are linked to the active transport of sodium. Short chains of two amino acids dipeptides or three amino acids tripeptides are also transported actively.

However, after they enter the absorptive epithelial cells, they are broken down into their amino acids before leaving the cell and entering the capillary blood via diffusion.

About 95 percent of lipids are absorbed in the small intestine. Bile salts not only speed up lipid digestion, they are also essential to the absorption of the end products of lipid digestion.

Short-chain fatty acids are relatively water soluble and can enter the absorptive cells enterocytes directly. Despite being hydrophobic, the small size of short-chain fatty acids enables them to be absorbed by enterocytes via simple diffusion, and then take the same path as monosaccharides and amino acids into the blood capillary of a villus.

The large and hydrophobic long-chain fatty acids and monoacylglycerides are not so easily suspended in the watery intestinal chyme. However, bile salts and lecithin resolve this issue by enclosing them in a micelle , which is a tiny sphere with polar hydrophilic ends facing the watery environment and hydrophobic tails turned to the interior, creating a receptive environment for the long-chain fatty acids.

The core also includes cholesterol and fat-soluble vitamins. Without micelles, lipids would sit on the surface of chyme and never come in contact with the absorptive surfaces of the epithelial cells.

Micelles can easily squeeze between microvilli and get very near the luminal cell surface. At this point, lipid substances exit the micelle and are absorbed via simple diffusion. The free fatty acids and monoacylglycerides that enter the epithelial cells are reincorporated into triglycerides.

The triglycerides are mixed with phospholipids and cholesterol, and surrounded with a protein coat. This new complex, called a chylomicron , is a water-soluble lipoprotein.

After being processed by the Golgi apparatus, chylomicrons are released from the cell. Too big to pass through the basement membranes of blood capillaries, chylomicrons instead enter the large pores of lacteals.

The lacteals come together to form the lymphatic vessels. The chylomicrons are transported in the lymphatic vessels and empty through the thoracic duct into the subclavian vein of the circulatory system. Once in the bloodstream, the enzyme lipoprotein lipase breaks down the triglycerides of the chylomicrons into free fatty acids and glycerol.

These breakdown products then pass through capillary walls to be used for energy by cells or stored in adipose tissue as fat. Liver cells combine the remaining chylomicron remnants with proteins, forming lipoproteins that transport cholesterol in the blood.

Figure 6. Unlike amino acids and simple sugars, lipids are transformed as they are absorbed through epithelial cells. The products of nucleic acid digestion—pentose sugars, nitrogenous bases, and phosphate ions—are transported by carriers across the villus epithelium via active transport.

These products then enter the bloodstream. The electrolytes absorbed by the small intestine are from both GI secretions and ingested foods.

Since electrolytes dissociate into ions in water, most are absorbed via active transport throughout the entire small intestine.

At least seven different carrier proteins transport different groups of amino acids across the enterocyte plasma membrane. Amino acids leave the enterocyte by a facilitative transporter on the basal-lateral surface of the enterocyte for entry into the blood.

A High Protein Meal Following ingestion of a high protein meal, the gut and the liver utilize most of the absorbed amino acids. Glutamate and aspartate are utilized as fuels by the gut, and very little enters the portal vein.

The gut may also use some branched chain amino acids. These amino acids, for the most part, are converted to glucose. After a pure protein meal, the increased levels of dietary amino acids reaching the pancreas stimulate the release of glucagon above fasting levels, thereby increasing amino acid uptake into the liver.

Insulin release is also stimulated, but not nearly to the levels found after a high carbohydrate meal figure at the right; click the image for a comparison with a carbohydrate meal and note the differences in the blood glucose, insulin and glucagon levels between a low or no carbohydrate protein meal and a high carbohydrate meal.

In general, the insulin released after a high protein meal is sufficiently high that net protein synthesis is stimulated, but gluconeogenesis in the liver is not inhibited. Most of the amino acid nitrogen entering the peripheral circulation after a high protein meal or a mixed meal is present as the branched chain amino acids leucine, isoleucine, valine.

Because the liver has low levels of transaminases for these amino acids, it cannot oxidize them to a significant extent and they enter the systemic circulation. The branched chain amino acids are taken up slowly by skeletal muscle and other tissues.

These peripheral non-hepatic tissues utilize the amino acids derived from the diet principally for net protein synthesis. Digestive proteases are synthesized as larger, inactive forms zymogens , which, after secretion, are cleaved to produce active proteases.

The amino acids indicated after the curly brace in the diagram below are the preferred amino acids at which each of the indicated enzymes cleaves. The monosaccharide fructose which is in fruit is absorbed and transported by facilitated diffusion alone.

The monosaccharides combine with the transport proteins immediately after the disaccharides are broken down. Active transport mechanisms, primarily in the duodenum and jejunum, absorb most proteins as their breakdown products, amino acids. Almost all 95 to 98 percent protein is digested and absorbed in the small intestine.

The type of carrier that transports an amino acid varies. Most carriers are linked to the active transport of sodium. Short chains of two amino acids dipeptides or three amino acids tripeptides are also transported actively.

However, after they enter the absorptive epithelial cells, they are broken down into their amino acids before leaving the cell and entering the capillary blood via diffusion. About 95 percent of lipids are absorbed in the small intestine.

Bile salts not only speed up lipid digestion, they are also essential to the absorption of the end products of lipid digestion. Short-chain fatty acids are relatively water soluble and can enter the absorptive cells enterocytes directly.

Despite being hydrophobic, the small size of short-chain fatty acids enables them to be absorbed by enterocytes via simple diffusion, and then take the same path as monosaccharides and amino acids into the blood capillary of a villus.

The large and hydrophobic long-chain fatty acids and monoacylglycerides are not so easily suspended in the watery intestinal chyme. However, bile salts and lecithin resolve this issue by enclosing them in a micelle , which is a tiny sphere with polar hydrophilic ends facing the watery environment and hydrophobic tails turned to the interior, creating a receptive environment for the long-chain fatty acids.

The core also includes cholesterol and fat-soluble vitamins. Without micelles, lipids would sit on the surface of chyme and never come in contact with the absorptive surfaces of the epithelial cells. Micelles can easily squeeze between microvilli and get very near the luminal cell surface.

At this point, lipid substances exit the micelle and are absorbed via simple diffusion. The free fatty acids and monoacylglycerides that enter the epithelial cells are reincorporated into triglycerides.

The triglycerides are mixed with phospholipids and cholesterol, and surrounded with a protein coat. This new complex, called a chylomicron , is a water-soluble lipoprotein. After being processed by the Golgi apparatus, chylomicrons are released from the cell. Too big to pass through the basement membranes of blood capillaries, chylomicrons instead enter the large pores of lacteals.

The lacteals come together to form the lymphatic vessels. The chylomicrons are transported in the lymphatic vessels and empty through the thoracic duct into the subclavian vein of the circulatory system.

Once in the bloodstream, the enzyme lipoprotein lipase breaks down the triglycerides of the chylomicrons into free fatty acids and glycerol.

These breakdown products then pass through capillary walls to be used for energy by cells or stored in adipose tissue as fat. Liver cells combine the remaining chylomicron remnants with proteins, forming lipoproteins that transport cholesterol in the blood. Figure 6. Unlike amino acids and simple sugars, lipids are transformed as they are absorbed through epithelial cells.

The products of nucleic acid digestion—pentose sugars, nitrogenous bases, and phosphate ions—are transported by carriers across the villus epithelium via active transport.

These products then enter the bloodstream. The electrolytes absorbed by the small intestine are from both GI secretions and ingested foods. Since electrolytes dissociate into ions in water, most are absorbed via active transport throughout the entire small intestine.

During absorption, co-transport mechanisms result in the accumulation of sodium ions inside the cells, whereas anti-port mechanisms reduce the potassium ion concentration inside the cells.

To restore the sodium-potassium gradient across the cell membrane, a sodium-potassium pump requiring ATP pumps sodium out and potassium in. In general, all minerals that enter the intestine are absorbed, whether you need them or not. Iron —The ionic iron needed for the production of hemoglobin is absorbed into mucosal cells via active transport.

Once inside mucosal cells, ionic iron binds to the protein ferritin, creating iron-ferritin complexes that store iron until needed. When the body has enough iron, most of the stored iron is lost when worn-out epithelial cells slough off.

When the body needs iron because, for example, it is lost during acute or chronic bleeding, there is increased uptake of iron from the intestine and accelerated release of iron into the bloodstream.

Since women experience significant iron loss during menstruation, they have around four times as many iron transport proteins in their intestinal epithelial cells as do men. Calcium —Blood levels of ionic calcium determine the absorption of dietary calcium.

When blood levels of ionic calcium drop, parathyroid hormone PTH secreted by the parathyroid glands stimulates the release of calcium ions from bone matrices and increases the reabsorption of calcium by the kidneys.

PTH also upregulates the activation of vitamin D in the kidney, which then facilitates intestinal calcium ion absorption. The small intestine absorbs the vitamins that occur naturally in food and supplements. Fat-soluble vitamins A, D, E, and K are absorbed along with dietary lipids in micelles via simple diffusion.

This is why you are advised to eat some fatty foods when you take fat-soluble vitamin supplements. Most water-soluble vitamins including most B vitamins and vitamin C also are absorbed by simple diffusion. An exception is vitamin B 12 , which is a very large molecule.

Intrinsic factor secreted in the stomach binds to vitamin B 12 , preventing its digestion and creating a complex that binds to mucosal receptors in the terminal ileum, where it is taken up by endocytosis.

Each day, about nine liters of fluid enter the small intestine. About 2. About 90 percent of this water is absorbed in the small intestine.

Water absorption is driven by the concentration gradient of the water: The concentration of water is higher in chyme than it is in epithelial cells. Thus, water moves down its concentration gradient from the chyme into cells.

As noted earlier, much of the remaining water is then absorbed in the colon. The small intestine is the site of most chemical digestion and almost all absorption. Chemical digestion breaks large food molecules down into their chemical building blocks, which can then be absorbed through the intestinal wall and into the general circulation.

Intestinal brush border enzymes and pancreatic enzymes are responsible for the majority of chemical digestion. The breakdown of fat also requires bile.

Most nutrients are absorbed by transport mechanisms at the apical surface of enterocytes. Exceptions include lipids, fat-soluble vitamins, and most water-soluble vitamins. With the help of bile salts and lecithin, the dietary fats are emulsified to form micelles, which can carry the fat particles to the surface of the enterocytes.

There, the micelles release their fats to diffuse across the cell membrane. The fats are then reassembled into triglycerides and mixed with other lipids and proteins into chylomicrons that can pass into lacteals. Other absorbed monomers travel from blood capillaries in the villus to the hepatic portal vein and then to the liver.

chylomicron: large lipid-transport compound made up of triglycerides, phospholipids, cholesterol, and proteins. lactase: brush border enzyme that breaks down lactose into glucose and galactose. lipoprotein lipase: enzyme that breaks down triglycerides in chylomicrons into fatty acids and monoglycerides.

maltase: brush border enzyme that breaks down maltose and maltotriose into two and three molecules of glucose, respectively. micelle: tiny lipid-transport compound composed of bile salts and phospholipids with a fatty acid and monoacylglyceride core.

pancreatic amylase: enzyme secreted by the pancreas that completes the chemical digestion of carbohydrates in the small intestine.

pancreatic lipase: enzyme secreted by the pancreas that participates in lipid digestion. pancreatic nuclease: enzyme secreted by the pancreas that participates in nucleic acid digestion. Skip to main content.

Module 7: The Digestive System.