Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
109 Cards in this Set
- Front
- Back
|
About 80 percent of water moves across the small intestinal lining and into the internal environment by
|
osmosis
|
|
|
anal sphincter
|
regulated the passage of fecal material from the body
|
|
|
Animal digestion involves four tasks
|
Ingestion: taking food into digestive chamber,Mechanical and chemical digestion: breaking down food into smaller components,Absorption: movement of nutrient molecules from digestive chamber to the internal environment,Elimination: expelling leftover material that was not digested and absorbed
|
|
|
Animal Digestive Systems
|
Some invertebrates have a saclike gut, but most animals have a tubular gut with two openings. Structural differences in digestive systems can arise as adaptations to different diets.
|
|
|
anus
|
opening to the outside
|
|
|
appendix
|
does not have a known function in humans
|
|
|
basal metabolic rate
|
Rate at which the body uses energy when you are at rest.
|
|
|
Bile
|
Mix of salts, pigments, and cholesterol produced in the liver, then stored and concentrated in the gallbladder; emulsifies fats when secreted into the small intestine.
|
|
|
brush border cell
|
In the lining of the small intestine, an epithelial cell with microvilli at its surface.
|
|
|
cardiac sphincter
|
valve controlling the flow of food from esophagus into stomach, prevents back flow of food
|
|
|
About 80 percent of water moves across the small intestinal lining and into the internal environment by
|
osmosis
|
|
|
anal sphincter
|
regulated the passage of fecal material from the body
|
|
|
Animal digestion involves four tasks
|
Ingestion: taking food into digestive chamber,Mechanical and chemical digestion: breaking down food into smaller components,Absorption: movement of nutrient molecules from digestive chamber to the internal environment,Elimination: expelling leftover material that was not digested and absorbed
|
|
|
Animal Digestive Systems
|
Some invertebrates have a saclike gut, but most animals have a tubular gut with two openings. Structural differences in digestive systems can arise as adaptations to different diets.
|
|
|
anus
|
opening to the outside
|
|
|
appendix
|
does not have a known function in humans
|
|
|
basal metabolic rate
|
Rate at which the body uses energy when you are at rest.
|
|
|
Bile
|
Mix of salts, pigments, and cholesterol produced in the liver, then stored and concentrated in the gallbladder; emulsifies fats when secreted into the small intestine.
|
|
|
brush border cell
|
In the lining of the small intestine, an epithelial cell with microvilli at its surface.
|
|
|
cardiac sphincter
|
valve controlling the flow of food from esophagus into stomach, prevents back flow of food
|
|
|
Chemical digestion
|
is completed in the small intestine. Enzymes from the pancreas and enzymes embedded in the membrane of brush border cells break large molecules into smaller, absorbable subunits. Bile made by the liver and stored in the gallbladder emulsifies fats, making it easier for enzymes to break them down. Small subunits (monosaccharides, amino acids, fatty acids, and monoglycerides) enter the internal environment when they are transported into brush border cells, then out into the interstitial fluid in a villus. Most fluid that enters the gut is also absorbed across the wall of the small intestine.By absorbing water and mineral ions, the colon compacts undigested residues and other wastes as feces, which are stored briefly in the rectum before expulsion.
|
|
|
Chyme
|
Mix of food and gastric fluid.
|
|
|
Cloaca
|
Body opening that serves as the exit for digestive and urinary waste; also functions in reproduction.
|
|
|
Compare the structure of an enzyme before and after a reaction.
|
No change in the enzyme.
|
|
|
Compare your body temperature to the optimum temperature of salivary amylase
|
37°C = Body temperature
|
|
|
complete digestive tract
|
Tubelike digestive system; food enters through one opening and wastes leave through another.
|
|
|
Dietary carbohydrates
|
are the body's main sources of energy. Dietary fats are broken down for energy, and used to make membrane components and steroid hormones.
|
|
|
Dietary proteins
|
...provide amino acids for building peptides, proteins, and nucleotides. Animal protein provides every amino acid a human body needs. Most plant proteins lack one or more essential amino acids, but combining plant foods can provide all you need.
|
|
|
Different components of the human digestive system specialize in
|
:Digesting food, absorbing nutrients, and concentrating and storing unabsorbed waste
|
|
|
Digestion and Absorption
|
Digestion is the mechanical and chemical breakdown of food into its component organic subunits. Absorption is transfer of these subunits from the interior of the gut into body tissues.
|
|
|
Digestive systems
|
mechanically and chemically degrade food into small molecules that can be absorbed into the internal environment. These systems also expel the undigested residues from the body. Some invertebrates digest food in a gastrovascular cavity that has one opening. Most animals have a tubular digestive tract with two openings and regional specializations in between. Some variations in gut structure reflect adaptations to particular diets.
|
|
|
Emulsification
|
Dispersion of fat droplets in a fluid.
|
|
|
Epiglottis
|
Flap that covers the trachea while swallowing
|
|
|
Esophagus
|
Muscular tube between the throat and stomach.
|
|
|
esophagus
|
passageway for food, peristalsis, no digestion
|
|
|
essential amino acid
|
Amino acid that the body cannot make and must obtain from food.
|
|
|
essential fatty acid
|
Fatty acid that the body cannot make and must obtain from food.
|
|
|
Essential fatty acids and essential amino acids
|
cannot be made by the body and must be obtained from food
|
|
|
Fats
|
: broken down into fatty acids and monoglycerides.Enzymes involved: lipases,Bile enhances fat digestion by facilitating emulsification: dispersion of droplets of fat
|
|
|
Features of animal digestive systems are shaped by
|
natural selection; animals are adapted to a particular diet, Shape of bird's beak determines food source, Four types of mammalian teeth are best suited for different types of food, Gizzard breaks down tough food in birds
|
|
|
Feces
|
Unabsorbed food material and cellular waste that is expelled from the digestive tract.
|
|
|
Flatworms and cnidarians have a saclike gastrovascular cavity:
|
functions in both digestion and gas exchange
|
|
|
Fruits, Vegetables, and Whole Grains
|
Fruits, vegetables, and grains should make up the largest proportion of your diet These foods provide sugars and starches, your primary sources of energy
|
|
|
gall bladder
|
acts as a storage sac for bile
|
|
|
Gallbladder
|
Organ that stores and concentrates bile.
|
|
|
gastric fluid
|
Fluid secreted by the stomach lining; contains digestive enzymes, acid, and mucus.
|
|
|
gastrovascular cavity
|
Saclike gut that also functions in gas exchange.
|
|
|
Heart-Healthy Oils
|
A healthy diet includes fats that provide energy and meet your need for essential fatty acids,Essential fatty acids are,polyunsaturated,Omega-3 fatty acids,Omega-6 fatty acids
|
|
|
How Are Components of Food Broken Down and Absorbed
|
Process of chemical digestion is completed in the small intestine,Chyme from the stomach, enzymes and bicarbonate from the pancreas, and bile from the gallbladder aid in chemical digestion,Carbohydrates: broken down into monosaccharides, or,simple sugars,Enzymes involved: salivary amylase, pancreatic amylase, sucrase, and lactase,Proteins: broken down into polypeptides and then into amino acids.Enzymes involved: pepsin, pancreatic proteases
|
|
|
How does litmus indicate that fat digestion has occurred?
|
It turns red (or dark pink)
|
|
|
How Does the Body Use Carbohydrates, Fats, and Proteins?
|
Dietary carbohydrates, fats, and proteins are macronutrients: substances that we require in large amounts Needed for energy and raw materials,Breakdown products of these molecules serve as reactants in aerobic respiration
|
|
|
How Does the Body Use Vitamins and Minerals?
|
Vitamins: organic substances that are required in the diet in very small amounts,Minerals: elements that are essential in the diet in small amounts
|
|
|
How Does the Structure of the Small Intestine Enhance Its Function?
|
Most digestion and absorption takes place at the lining of the small intestine/The many folds and projections of the small intestinal lining increase its surface area by hundreds of times,Villi: multicelled projections,Microvilli: thin projections that increase the surface area of epithelial cells,Brush border cells: epithelial cell with microvilli Like the stomach, the small intestine has three layers of smooth muscle,Muscles mix chyme, propel it forward, and force it up against the wall of the small intestine to enhance the rate of digestion and absorption
|
|
|
How were you able to determine when starch digestion was complete?
|
Lugol's solution turns blue/black in the presence of starch. If the starch has been digested to sugar, Lugol's solution will remain amber color
|
|
|
How will you know when the starch has been converted into sugar?
|
The solution will not turn blue/black, since starch has been digested into sugar.
|
|
|
Human Digestive System
|
Human digestion starts in the mouth and continues in the stomach and small intestine.Nutrient absorption begins in the small intestine. The large intestine concentrates wastes.Humans have a complete digestive system. Food processing starts in the mouth. Swallowing forces food and water from the mouth into the pharynx. Food continues through an esophagus to the stomach. Most digestion and absorption occurs in the small intestine. The large intestine absorbs most of the remaining water and ions, which causes the wastes to compact. The rectum briefly stores the wastes before they are expelled through the anus. The liver and pancreas produce substances that are secreted into the small intestine.The stomach receives food from the esophagus and stretches to store it. Stomach contractions break up food and mix it with gastric fluid. They also move the resulting mixture (the chyme) into the small intestine. Chemical digestion of proteins begins in the stomach.
|
|
|
Human Nutrition
|
A healthy diet provides all nutrients, vitamins, and minerals necessary to build body parts and maintain normal metabolism. It is low in salt, simple sugars, and saturated fats.
|
|
|
ileocecal valve
|
controls passage of food from small intestine to large intestine
|
|
|
large intestine
|
storage and concentration of feces
|
|
|
Lean Meat and Low-Fat Dairy
|
Meat (including poultry and fish) is the richest source of protein and is also rich in essential iron,Eating soybean products provides complete protein without harmful fats or cholesterol,Milk and dairy products are good sources of protein, vitamins, and minerals, but whole milk is rich in saturated fats
|
|
|
liver
|
Many hormones and drugs, such as alcohol, are broken down by the liver. The liver produces bile that is used in the small intestine to emulsify lipids and fats into smaller particles.
|
|
|
Maintaining a Healthy Weight
|
Maintaining body weight requires balancing calories taken in with calories burned. A body weight far above or below normal increases the risk of health problems.A person who balances caloric intake with energy expenditures will maintain his or her current weight. The rate at which your body uses energy is influenced by age,body size and muscularity, and thyroid hormone level. Physical activity expends energy and can help reduce body weight by increasing basal metabolic rate.
|
|
|
Microvilli
|
Thin projections that increase the surface area of some epithelial cells.
|
|
|
mineral
|
In the diet, an inorganic substance that is required in small amounts for normal metabolism.
|
|
|
Most invertebrates and all vertebrates have a complete digestive tract
|
: a tubular gut with two openings
|
|
|
mouth
|
mechanical breakdown of food by teeth, salivary amylase begins starch digestion, food formed into bolus
|
|
|
Normal metabolism
|
requires dietary intake of essential vitamins and inorganic substances called minerals. Fat-soluble vitamins are stored in the body. Water-soluble ones are not, and must be replenished more often. Many vitamins function as antioxidants or are made into coenzymes. Essential minerals are components of important biological molecules.Fresh fruits, vegetables, and whole grains in the diet provide carbohydrates and also vitamins, minerals, and dietary fiber essential to health. Meat and dairy products are rich sources of protein, and meat provides iron. These animal products can also be high in saturated fats, which elevate risk of heart disease. Processed foods are high in sodium and sugars. Excessive sodium intake increases the risk of high blood pressure. Sugar adds calories without adding nutritional value.
|
|
|
pancreas
|
Secretes enzymes into the duodenum that digest carbohydrates, fats, proteins, and nucleic acids. Secretes bicarbonate ions that neutralize the HCl from the stomach. Produces insulin; secreted directly into the bloodstream, insulin regulates blood sugar.
|
|
|
Peristalsis
|
Wavelike smooth muscle contractions that propel food through the digestive tract.
|
|
|
pharynx
|
passageway for food and air, no role in digestion
|
|
|
Predict the optimum temperature for salivary amylase activity.
|
Body temperature: 37
|
|
|
pyloric sphincter
|
controls the passage of chyme into small intestine
|
|
|
Rectum
|
Region where feces are stored prior to excretion.
|
|
|
rectum
|
storage area continuous with large intestine
|
|
|
rugae
|
ridges in the stomach lining that increase surface area for digestion
|
|
|
Ruminant
|
Hoofed mammal with a multiple-chamber stomach that adapts it to a cellulose-rich diet.
|
|
|
Ruminants (hoofed grazers)
|
have multiple stomach chambers and beneficial microbes
|
|
|
salivary gland
|
Exocrine gland that secretes saliva into the mouth.
|
|
|
Salivary glands, the pancreas, and the liver are
|
accessory organs that secrete substances into the tube
|
|
|
small intestine
|
digestion completed, most nutrients are absorbed
|
|
|
Stomach
|
Digestive organ that mixes food with enzymes and acid.
|
|
|
stomach
|
hydrochloric acid production, protein digestion begins, bolus becomes chyme, rugae are folds that increase the surface area of the stomach to increase storage capacity
|
|
|
Stomach disorders
|
Gastroesophageal reflux:sphincter at the entrance of stomach is dysfunctional; acidic chyme splashes into the esophagus,Stomach ulcers: typically arises after H. pylori releases chemicals that increase gastrin secretion.Also caused by continual use of nonsteroidal anti-inflammatory drugs, which inhibit the release of protective mucus
|
|
|
The human stomach is
|
a muscular, stretchable sac with a sphincter (ring of muscle) at either end
|
|
|
The stomach has three functions:
|
Stores food; controls rate of passage to small intestines,Mechanically breaks down food.Secretes substances that aid in chemical digestion
|
|
|
The surface of the small intestine is
|
highly folded. Each fold has many fingerlike projections (villi). Brush border cells at the surface of a villus have tiny cylindrical projections (microvilli) at their surface. The many folds and projections of the intestinal lining greatly increase the surface area for the two functions of the small intestine—digestion and absorption.
|
|
|
Two types of fiber
|
: soluble fiber and insoluble fiber,Eating foods high in soluble fiber helps lower one's cholesterol level and reduces the risk of heart disease,Whole grains provide more vitamins and fiber than their processed counterparts A whole grain includes all components of a grain seed White wheat flour is made solely from endosperm
|
|
|
villi
|
finger-like projections that line the small intestine that increase surface area for nutrient absorption
|
|
|
Villi
|
Multicelled projections from the lining of the small intestine.
|
|
|
Vitamin
|
Organic substance required in the diet in small amounts for normal metabolism.
|
|
|
What Are the Functions of the Large Intestine?
|
Substances move from the small intestine to the large intestine:,Indigestible material, dead bacteria and mucosal cells, inorganic substances, and some water,As wastes travel through the large intestine, they become compacted as feces The first part of the large intestine is a cup-shaped pouch called the cecum,An herbivore cecum contains many bacteria that help breakdown cellulose,In humans and many other mammals, a short, tubular appendix projects from the cecum Serves as a reservoir for beneficial bacteria
|
|
|
What are the products?
|
Monoglycerides and Fatty Acids
|
|
|
What color indicates a negative test for starch?
|
Amber
|
|
|
What color indicates a positive test for starch?Blue
|
black
|
|
|
What Determines Our Weight?
|
When the food you eat contains more energy than you need, you store the excess as bond energy in organic compounds,The body's largest energy store is fat in adipose tissue,For most of our species' history, an ability to store energy as fat in adipose tissue was selectively advantageous However, most people in the United States now have more than enough food all of the time As a result, about two-thirds of adults are overweight or obese,Body mass index (BMI) is a measurement designed to help assess increased health risk associated with weight,Body mass index formula:BMI = weight (pounds) × 703 height (inches) × height (inches)Generally, individuals with a BMI of 25 to 29.9 are said to be overweight,A score of 30 or more indicates obesity: an overabundance of fat in adipose tissue that may lead to severe health problems,To maintain a given weight, you must balance the amount of energy in the food you eat with the energy you expend in your activities
|
|
|
What enzyme begins starch digestion?
|
Salivary amylase
|
|
|
What enzyme is involved?
|
Lipase
|
|
|
What enzyme produced in the pancreas digests fat?
|
Lipase
|
|
|
What happens to the speed of a reaction if an enzyme is boiled? Why
|
Stops. The enzyme is denatured (enzyme unfolds & active site destroyed)
|
|
|
What is indicated when litmus turns red?
|
Presence of an acid (fatty acid)
|
|
|
What is the enzyme in the reaction?
|
Salivary amylase
|
|
|
What is the function of the villi in the small intestine? Include the role of the capillaries and lymph vessels.
|
Increases surface area for absorption.Sugars and amino acids enter the capillaries and the products of fat digestion enter the lymph vessels.
|
|
|
What is the product in the reaction?
|
Maltose
|
|
|
What is the purpose of the litmus solution in the fat digestion experiment
|
Determines when lipids are digested to fatty acids because a color change occurs from blue to pink
|
|
|
What is the substrate in the reaction above?
|
Fat
|
|
|
What is the substrate in the reaction?
|
Starch
|
|
|
What occurs at the active site of an enzyme?
|
Substrate loosely binds to enzyme
|
|
|
Which color do you predict will be the result of the complete starch digestion?
|
Amber will indicate that no starch remains, as it was digested into sugar.
|
|
|
Why is bile needed for fat digestion?
|
Emulsification of fat (breaks fat into small droplets) results in increased rate of fat digestion.
|
