Biology Exam 3: Chapter 33

Examine the digestive system structures in the figure above. Most of the digestion of fats occurs in location(s) 1 and 4. 4 only. 1, 3, and 4. 3 only. 3 and 4.

4 only

Examine the digestive system structures in the figure above. The most enzymatic hydrolysis of macromolecules occurs at location(s) 1, 3, and 4. 3 and 4. 3 only. 4 only. 1 and 4.

4 only

_____ is secreted by the _____ and acts to emulsify _____ in the _____. Amylase ... salivary glands ... starch ... stomach Lipase ... small intestine ... fats ... small intestine Trypsin ... pancreas ... fats ... small intestine Bile ... liver ... fats ... small intestine Nucleases ... pancreas ... nucleic acids ... stomach

Bile... liver... fats... small intestine

Choose the correct statement from the list below. Bile salts from the gall bladder are essential to the digestion of carbohydrates. Carbohydrate absorption occurs primarily in the large intestine. Carbohydrate digestion begins in the mouth with salivary amylase. Carbohydrates are fully digested after passage through the stomach .

Carbohydrate digestion begins in the mouth with salivary amylase

True or False? The liver is a component of the alimentary canal. True False

False

True or false? One advantage of having a tube-like digestive tract is that digestion of all compounds can take place simultaneously down the tract. True False

False

Choose the correct statement from the list below. Free fatty acid absorption occurs in the small intestine. Fat digestion begins in the stomach with the activation of trypsinogen to trypsin. Fats are fully digested after passage through the mouth and stomach. Bile salts from the pancreas are essential to the digestion of fats

Free fatty acid absorption occurs in the small intestine

Many people have a tendency to gorge on rich, fatty foods. How could such a preference have evolved? In ancestral hunter-gatherer communities, individuals with a tendency to gorge on such foods when available would have had a selective advantage Fatty foods are very rich in calories and consuming them is an efficient way to gain weight. Most people find fatty foods tasty and satisfying.

In ancestral hunter-gatherer communities, individuals with a tendency to gorge on such foods when available would have a selective advantage

In the process of intracellular digestion, what do you predict will happen if food vacuoles are unable to fuse with lysosomes? Cells will not be able to engulf solid food by pinocytosis. The food to be digested will not be able to come in contact with hydrolytic enzymes. Cells will not be able to engulf liquid food by phagocytosis. The cells will not be able to utilize their hydrolytic enzymes.

The cells will not be able to utilize their hydrolytic enzymes

Consider the interior surface of the human stomach and its secretions, shown in the figure. Why doesn't gastric juice, composed of hydrochloric acid and a protease called pepsin, digest the cells that line the stomach? Chief cells release pepsin in an inactive form. HCl in the stomach converts pepsin to an active form of the enzyme called pepsinogen by clipping off a small portion of the molecule to expose its active site. The stomach lining secretes mucus, a mixture of glycoproteins, cells, salts, and water Digestion doesn't begin until the small intestine.

The stomach lining secretes mucus, a mixture of glycoproteins, cells, salts, and water

A general rule relating the capacity of a specific animal's digestive system to provide adequate access to substrates for biosynthesis of cellular components, as well as fuel molecules needed for ATP production, is that the animal should have access to a high-protein, low-carbohydrate diet.a diet low in lipids and high in protein. a low-calorie diet with a large intake of fluids, especially water. a diet that maximizes vitamins and minerals. a diet that matches chemical energy, essential nutrient, and organic molecule building blocks per species.

a diet that matches chemical energy, essential nutrient, and organic molecule building blocks per species

Stomach cells are moderately well adapted to the acidity and protein-digesting activities in the stomach by having a high level of secretion by chief cells. a thick, mucous secretion and active mitosis of epithelial cells. a high level of secretion from parietal cells.a thriving colony of H. pylori. secretions that enter the stomach from the pancreas.

a thick, mucous secretion and active mitosis of epithelial cells,

Ingested dietary substances must cross cell membranes to be used by the body, a process known as elimination. absorption. ingestion. hydrolysis. digestion.

absorption

The large surface area in the small intestine directly facilitates absorption. elimination. filtration temperature regulation. secretion.

absorption

Nucleic acid digestion yields nucleotides, whereas protein digestion yields amino acids; both digestive processes are catalyzed by the same enzyme. require ATP as an energy source. require the presence of hydrochloric acid to lower the pH. add a water molecule to break bonds (hydrolysis).

add a water molecule to break bonds (hydrolysis)

Fat digestion yields fatty acids and glycerol. Protein digestion yields amino acids. Both digestive processes __________. require a low pH resulting from HCl production consume ATP add a water molecule to break bonds occur inside cells in most animals

add water molecule to break bonds

An advantage of a complete digestive system over a gastrovascular cavity is that the complete system allows for extensive branching. allows for specialized regions with specialized functions. excludes the need for extracellular digestion. allows digestive enzymes to be more specific. facilitates intracellular digestion.

allows for specialized regions with specialized functions

When digested, proteins are broken down into _____. glycerol only fatty acids only monosaccharides amino acids both glycerol and fatty acids

amino acids

To survive, all animals must _____. ingest nutrients from the environment every day of their lives balance consumption of food with use and storage of nutrients have a complete digestive system digest plant material hibernate

balance consumption of food with use and storage of nutrients

Pepsin is a digestive enzyme that is manufactured by the pancreas. splits maltose into monosaccharides. begins the hydrolysis of proteins in the stomach. helps stabilize fat-water emulsions. is denatured and rendered inactive in solutions with low pH.

begins the hydrolysis of proteins in the stomach

When digested, fats are broken down into _____. glycerol only fatty acids only monosaccharides amino acids both glycerol and fatty acids

both glycerol and fatty acids

Standard metabolic rate (SMR) and basal metabolic rate (BMR) are used to compare metabolic rate between hibernating and nonhibernating states. both standard measurements of fat metabolism in mammals. both measured across a wide range of temperatures for a given species. both measured in animals experiencing a resting and fasting state. used differently: SMR is measured during exercise, whereas BMR is measured at rest

both measured in animals experiencing a resting and fasting state.

Bacteria in the human gut are which of the following? all mutualists both pathogens and mutualists all pathogens

both pathogens and mutualists

The "essential nutrients" for proper human nutrition include _____. active enzymes from plants and/or animals cellulose glucose all of the amino acids calcium, sodium, potassium, and other minerals

calcium, sodium, potassium, and other minerals

To maintain adequate nutrition, animals require dietary access to certain amino acids. An amino acid that is referred to as "nonessential" would be best described as one that can be made by the animal's body from other substances. is not used by the animal in biosynthesis. must be ingested in the diet. is not found in many proteins. is not readily absorbed by the gastrointestinal tract.

can be made by the animals body from other substances

Different types of food are eaten by various groups of animals, but it is usually true that _____. the intestines of carnivores tend to be longer than the intestines of herbivores of similar overall body size the teeth of herbivores tend to be sharper than the teeth of carnivores animals typically produce enzymes that hydrolyze cellulose cellulose digestion in ruminant mammals occurs before the ingested foods reach the small intestine many carnivorous vertebrates house large populations of symbiotic bacteria and protists in special fermentation chambers in their stomachs

cellulose digestion in ruminant mammals occurs before the ingested foods reach the small intestine

The presence of fatty acids and amino acids in the chyme from the stomach triggers the small intestine to secrete a hormone known as _____. cholecystokinin, or CCK histones insulin secretin thyroxine

cholecystokinin, or CCK

Earthworms, grasshoppers, and birds all have a larynx. gastric cecae. crop. epiglottis. pharynx.

crop

Bile salts are enzymes. increase the efficiency of pepsin action. emulsify fats in the duodenum. are manufactured by the pancreas. are normally an ingredient of gastric juice.

emulsify fats in the duodenum

Because the foods eaten by animals are often composed largely of macromolecules, this requires the animals to have mechanisms for enzymatic hydrolysis. excretion. regurgitation. dehydration synthesis.

enzyme hydrolysis

Select the correct statement about essential nutrients. Essential nutrients must be obtained from diet. All animals require an identical set of essential nutrients. Due to their biochemical sophistication, humans have to ingest fewer essential nutrients than do other animals.

essential nutrients must be obtained from diet

Which process is not required for an animal to obtain energy from food? Digestion. Ingestion. Excretion. Secretion.

excretion

After surgical removal of the gallbladder, a person might need to limit their dietary intake of __________. starch fat protein sugar

fat

The richest source of stored chemical energy in the body is protein in muscle cells. fat in adipose tissue. calcium phosphate in bone. glucose in the blood. glycogen in muscle cells.

fat in adipose tissue

Your small intestine can absorb ____ without its being further digested. nucleic acid fat fructose starch protein

fructose

The molar teeth of herbivorous mammals are especially effective at cutting. ripping. grinding. crushing.

grinding

The gastrovascular cavity differs from the alimentary canal in that only the gastrovascular cavity __________. functions in digestion but not absorption stores food but does not digest it has only a single opening absorbs food molecules but does not produce hydrolytic enzymes is capable of extracellular digestion

has only a single opening

Choose the list that presents the four stages of food processing in the order in which they naturally occur. digestion → ingestion → absorption → elimination absorption → digestion → ingestion → elimination ingestion → digestion → elimination → absorption ingestion → digestion → absorption → elimination ingestion → absorption → elimination → digestion

ingestion--> digestion--> absorption--> elimination

After eating a carbohydrate-rich meal, the mammalian pancreas increases its secretion of glucagon. mucus. insulin. bile salts.

insulin

Which organ is INCORRECTLY paired with its function? pancreas - enzyme production stomach - protein digestion small intestine - nutrient absorption large intestine - bile production

large intestine- bile production

Bile is produced by the _____ and stored by the _____ until it is secreted into the small intestine. liver ... gall bladder pancreas ... gall bladder liver ... pancreas gall bladder ... liver esophagus ... stomach

liver... gall bladder

Starch can be broken down into the disaccharide known as _____. fructose lactose glucose maltose sucrose

maltose

The absorption of fats differs from that of carbohydrates in that the most absorbed fat first enters the lymphatic system, whereas carbohydrates directly enter the blood. processing of fats does not require any digestive enzymes, whereas the processing of carbohydrates does. fat absorption occurs in the stomach, whereas carbohydrates are absorbed from the small intestine. fats, but not carbohydrates, are digested by bacteria before absorption. carbohydrates need to be emulsified before they can be digested, whereas fats do not.

most absorbed fat first enters the lymphatic system. whereas carbohydrates directly enter the blood

For ingested foods, the first opportunity for mechanical digestion occurs in the _____. pancreas mouth large intestine small intestine stomach

mouth

Which pair correctly associates a physiological process with the appropriate vitamin? protection of skin from cancer and vitamin E production of white blood cells and vitamin K synthesis of cell membranes and vitamin D normal vision and vitamin A blood clotting and vitamin C

normal vision and vitamin A

Which of the following is NOT a major activity of the stomach? HCl production storage nutrient absorption enzyme secretion

nutrient absorption

Secretin stimulates the _____ to secrete _____. pancreas ... bicarbonate pancreas ... pancreatic enzymes small intestine ... disaccharidases stomach ... bicarbonate liver ... liver enzymes

pancreas... bicarbonate

Cholecystokinin (CCK) stimulates the _____ to secrete _____. pancreas ... bicarbonate pancreas ... pancreatic enzymes small intestine ... disaccharidases stomach ... bicarbonate liver ... liver enzymes

pancreas... pancreatic enzymes

An enzyme with high activity in an acidic environment is amylase. sucrose. trypsin. gastrin. pepsin.

pepsin

The mammalian trachea and esophagus both connect to the __________. large intestine rectum stomach pharynx

pharynx

Choose the correct anatomical sequence that presents the order in which food in the digestive system passes through. pharynx → small intestine → large intestine → stomach esophagus → pharynx → stomach → small intestine pharynx → esophagus → stomach → small intestine → large intestine esophagus → stomach → pharynx → small intestine pharynx → stomach → esophagus → small intestine

pharynx--> esophagus--> stomach--> small intestine--> large intestine

Starch is a type of _____. disaccharide fatty acid monosaccharide polysaccharide nucleotide

polysaccharide

Glandular secretions that are released initially as inactive precursors of digestive enzymes are the\ fat-solubilizing bile salts. hormones such as gastrin. acid-neutralizing bicarbonate. protein-digesting enzymes. carbohydrate-digesting enzymes.

protein=digesting enzymes

Choose the correct statement from the list below. Mechanical digestion of proteins is more important than chemical digestion. Proteins that are consumed in the diet are absorbed as individual amino acids following digestion. Protein digestion begins in the small intestine with the activation of trypsinogen to trypsin The stomach has a high pH which allows for the activation of digestive enzymes.

proteins that are consumed in the diet are absorbed as individual amino acids following digestion

An enlarged cecum is typical of carnivorous animals. rabbits, horses, and herbivorous bears. tubeworms that digest via symbionts. tapeworms and other intestinal parasites. humans and other primates.

rabbits, horses, and herbivorous bears.

The lower esophageal sphincter surrounds the upper opening into the stomach. If this sphincter failed to properly constrict, there might be a problem with _____. the control of defecation regurgitation of acidic stomach contents into the esophagus, commonly called "heartburn" too rapid emptying from the stomach into the small intestine too rapid emptying of the small intestine into the large intestine the movement of swallowed food into the trachea rather than into the esophagus

regurgitation of acidic stomach contents into the esophagus, commonly called "heartburn"

Which structure is not part of the alimentary canal? Mouth. Esophagus. Stomach. Salivary glands.

salivary glands

The acidity of the stomach contents triggers the small intestine to secrete a hormone known as _____. cholecystokinin, or CCK histones TSH secretin pepsin

secretin

In the digestive system, peristalsis is a common cause of loss of appetite, fatigue, and dehydration. smooth muscle contractions that move food along the esophagus. the transport of nutrients to the liver through the hepatic portal vein. voluntary control of the rectal sphincters regulating defecation. a process of fat emulsification in the small intestine.

smooth muscle contractions that move food along the esophagus

Digestive secretions with a pH of 2 are characteristic of the stomach. pancreas. liver. mouth. small intestine.

stomach

When the digestion and absorption of carbohydrates result in more energy-rich molecules than are immediately required by an animal, the excess is stored as glycogen in the liver and muscles. stored as starch in the liver. hydrolyzed and converted to ADP. oxidized and converted to ATP. eliminated in the feces.

stored as glycogen in liver and muscles

Analysis of jawbones from the skeletal remains of a vertebrate animal reveal its dietary patterns owing to whether the mouth is the most anterior structure. the size of the mouth opening. the evidence of food molecules still present. the position of muscle attachment sites. the prevalence of specific kinds of teeth.

the prevalence of specific kinds of teeth

Metabolic rate is _____. determined when the organism is vigorously exercising after consuming a fatty meal the amount of heat gained by an animal in a unit of time the total amount of energy an animal uses in a unit of time typically higher in an ectothermic animal than in an endothermic one directly proportional to body size

the total amount of energy an animal uses in a unit of time

Cattle are able to survive on a diet consisting almost entirely of plant material because they are autotrophic. they have cellulose-digesting, mutualistic microorganisms in chambers of their stomachs. they manufacture all 15 amino acids out of sugars in the liver. cattle saliva has enzymes capable of digesting cellulose. cattle, like rabbits, re-ingest their feces.

they have cellulose-digesting, mutualistic microorganisms in chambers of their stomachs

Identify the roles played by human gut bacteria. Human gut bacteria synthesize all essential vitamins required by humans. The human appendix houses mutualistic bacteria that digest cellulose. Ulcers are caused by the acid-tolerant bacterium Helicobacter pylori.

ulcers are caused by the acid-tolerant bacterium Helicobacter pylori

Among humans, increased interest in food intake normally occurs _____. only after the production of glucose in the liver can no longer meet metabolic needs via chemical signals related to the amount of glucose stored in the liver and muscle cells via chemical signals related to the amount of protein stores in the liver when fewer calories are taken in than are expended, but only after the body depletes its reserves of fat in the liver via chemical signals released when the stomach is empty

via chemical signals released when the stomach is empty

The fat-soluble vitamins include vitamin B12. iodine. calcium. vitamin A. vitamin C.

vitamin A

What is the main component of gastric juice? water amylase bile inactive pepsin hydrochloric acid

water