Digestive System Module 7: Chemical Digestion

Digestion begins in the mouth, where food is mechanically broken down.

The primary purpose of chemical digestion is to reduce food into its chemical building blocks for absorption.

Mechanical digestion involves the physical breakdown of food, while chemical digestion alters its chemical structure.

<p>Most nutrient absorption occurs in the small intestine.</p> Signup and view all the answers

<p>The nutrients that undergo chemical digestion include carbohydrates, proteins, lipids, and nucleic acids.</p> Signup and view all the answers

<p>Hydrophilic nutrients are absorbed through water channels, while hydrophobic nutrients are incorporated into micelles for absorption.</p> Signup and view all the answers

<p>Enzymes facilitate the breakdown of food into smaller, absorbable molecules during chemical digestion.</p> Signup and view all the answers

<p>After absorption, nutrients are transported to cells throughout the body to provide energy and support various functions.</p> Signup and view all the answers

<p>The main components are free fatty acids and monoglycerides.</p> Signup and view all the answers

<p>The majority of lipid digestion occurs in the small intestine.</p> Signup and view all the answers

<p>The two types are nucleases.</p> Signup and view all the answers

<p>The primary goal is to convert food into absorbable molecules.</p> Signup and view all the answers

<p>Carbohydrates are digested into monosaccharides, including glucose, galactose, and fructose.</p> Signup and view all the answers

<p>The two forms are dipeptides and tripeptides.</p> Signup and view all the answers

<p>A healthy diet limits lipid intake to 35 percent of total calorie intake.</p> Signup and view all the answers

<p>Enzymes break down large food molecules into smaller subunits that can be absorbed by the alimentary canal.</p> Signup and view all the answers

<p>The absorbable substances are pentose sugars, phosphates, and nitrogenous bases.</p> Signup and view all the answers

<p>Starch digestion begins in the mouth and continues in the small intestine, where pancreatic amylase breaks it down into simple sugars.</p> Signup and view all the answers

<p>Brush border enzymes break down disaccharides into monosaccharides, which can then be absorbed into the bloodstream.</p> Signup and view all the answers

<p>Protein digestion begins in the stomach, where hydrochloric acid (HCl) and pepsin break down proteins into smaller subunits.</p> Signup and view all the answers

<p>Chymotrypsin and trypsin are pancreatic enzymes that continue the digestion of proteins in the small intestine.</p> Signup and view all the answers

<p>About 50 percent of an average American's diet consists of carbohydrates.</p> Signup and view all the answers

<p>The final products of carbohydrate digestion are monosaccharides, which are the simplest form of sugars.</p> Signup and view all the answers

<p>After protein digestion, amino acids are small enough to enter the bloodstream through the intestinal lining.</p> Signup and view all the answers

<p>Indigestible food residue, mainly plant fibers like cellulose, some water, and bacteria.</p> Signup and view all the answers

<p>Active transport involves the movement of substances across a cell membrane from an area of lower concentration to higher concentration using cellular energy (ATP).</p> Signup and view all the answers

<p>Carbohydrates are absorbed in the form of monosaccharides.</p> Signup and view all the answers

<p>95 to 98 percent of protein is digested and absorbed in the small intestine.</p> Signup and view all the answers

<p>Bile salts speed up lipid digestion and are essential for the absorption of the products of lipid digestion.</p> Signup and view all the answers

<p>Lipid subunits enter large pores of lacteals, which form lymphatic vessels and are part of the lymphatic system.</p> Signup and view all the answers

<p>Indigestible fibers are eliminated in the feces.</p> Signup and view all the answers

<p>Most protein absorption occurs primarily in the duodenum and jejunum.</p> Signup and view all the answers

<p>α-dextrinase is a brush border enzyme that acts on α-dextrins to break them down into simpler sugars.</p> Signup and view all the answers

<p>Lipoprotein lipase breaks down triglycerides in chylomicrons into fatty acids and monoglycerides.</p> Signup and view all the answers

<p>Brush border enzymes such as lactase break down carbohydrates, specifically lactose, into glucose and galactose.</p> Signup and view all the answers

<p>Pancreatic amylase completes the chemical digestion of carbohydrates in the small intestine.</p> Signup and view all the answers

<p>A micelle is a tiny lipid-transport compound composed of bile salts and phospholipids with a fatty acid and monoacylglyceride core.</p> Signup and view all the answers

<p>Pentose sugars, nitrogenous bases, and phosphate ions.</p> Signup and view all the answers

<p>Water absorption is driven by the concentration gradient, where water moves from chyme into epithelial cells due to higher concentration in the chyme.</p> Signup and view all the answers

<p>Bile salts and lecithin emulsify dietary fats to form micelles, enabling fat particles to diffuse across intestinal cell membranes.</p> Signup and view all the answers

<p>Unlike amino acids and simple sugars, lipids are transformed as they are absorbed and require formation of micelles for transport.</p> Signup and view all the answers

<p>The small intestine is the primary site for nutrient absorption.</p> Signup and view all the answers

<p>Chylomicrons are formed by reassembling triglycerides along with other lipids and proteins after fat absorption.</p> Signup and view all the answers

<p>About 90 percent of the fluid entering the small intestine is absorbed.</p> Signup and view all the answers

<p>Most nutrients travel from the blood capillaries in the villus to the hepatic portal vein and then to the liver.</p> Signup and view all the answers