BIO 191 CH 33 HW

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

fructose Fructose is a monosaccharide, and monosaccharides can be absorbed without having to be broken down into smaller units.

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 Bile is continuously produced by the liver and is stored in the gall bladder until CCK triggers its release.

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

maltose Starch is composed of many maltose units.

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

water Water is the primary component of many secretions, including gastric juice.

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

secretin The acidity of the stomach contents triggers the small intestine to secrete secretin; secretin then stimulates the pancreas to secrete bicarbonate to neutralize this acidity.

An animal's body maintains a relatively constant internal environment. How is this accomplished? It is surprisingly similar to the way a thermostat and heating system maintain a relatively constant temperature inside a room. The diagram below shows how a thermostat responds when the temperature becomes too hot or too cold. Drag the terms on the left to the appropriate blanks on the right to complete the sentences. Not all terms will be used. 1. This heating system maintains room temperature at or near a particular value, known as the ______. 2. You open the window, and a blast of icy air enters the room. The temperature drops to 17 degrees Celsius, which acts as a ______to the heating system. 3. The thermostat is a ____ that detects the stimulus and triggers a response. 4. The heater turns on, and the temperature in the room ____ until it returns to the original setting. 5. The response of the heating system reduces the stimulus. This is an example of _____ feedback. 6. The way this heating system maintains a stable room temperature is similar to the way an animal's body controls many aspects of its internal environment. The maintenance of a relatively constant internal environment is known as ______.

1. set point 2. stimulus 3. sensor 4. increases 5. negative 6. homeostasis The maintenance of a relatively constant internal environment is known as homeostasis. To achieve homeostasis, the body has a wide variety of sensors that detect and trigger responses to different stimuli. Negative feedback, in which the body's response reduces the stimulus, is an important mechanism for maintaining homeostasis.

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

Bile ... liver ... fats ... small intestine Bile, produced by the liver and stored by the gall bladder, emulsifies fats in the small intestine. The smaller fat droplets present a greater surface area for the action of lipases.

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

Carbohydrate digestion begins in the mouth with salivary amylase. Carbohydrate digestion begins with the action of salivary amylase in the mouth

If the results had been identical for pairings (a) and (b), what conclusion would you have drawn? Differences in db genotype account for the observed change in body mass. Differences in ob genotype account for the observed change in body mass. Differences in ob genotype do not affect the change in body mass of the mice.

Differences in ob genotype do not affect the change in body mass of the mice.

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

Excretion. Excretion of wastes is NOT required for an animal to obtain energy from food.

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

False False. The alimentary canal is the tube through which food passes, beginning at the mouth and ending at the anus. The liver is an accessory organ of digestion and not part of the actual canal through which food passes.

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 One advantage of having a tube-like digestive tract is that digestive processes with different requirements (for example, an acidic or basic environment) can be separated within the tract.

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

Free fatty acid absorption occurs in the small intestine. Fat digestion is not complete until pancreatic lipases finalize fat digestion in the small intestine.

In what way did pairing (a) serve as a unique experimental control? Only in pairing (a) were changes in the body mass of the subject mice calculated. Only in pairing (a) were both mice wild-type for both genes. Only in pairing (a) were the subject mice joined surgically to other mice. Only in pairing (a) were the subject mice provided with unlimited access to food and water.

Only in pairing (a) were both mice wild-type for both genes. Pairing (a) served as a control for the experiment because the subject mice and their partners were wild-type for both genes. Therefore, the results from this pairing served as a baseline against which to compare the results from the other pairings, in which the subject mice and/or their partners were mutant for the ob or db gene.

In this experiment, mice of specific genotypes were paired together. Which of the following statements about the genotype pairings is correct? Pairing (a) joined two mice that were mutants for both the ob and db genes. Pairing (b) joined two mice that were mutants for the ob gene but wild-type for the db gene. Pairing (c) joined a wild-type mouse with one that was a mutant for the db gene. Pairing (d) joined a wild-type mouse with one that was a mutant for the db gene.

Pairing (b) joined two mice that were mutants for the ob gene but wild-type for the db gene.

In the disorder diabetes mellitus, the body is unable to maintain homeostasis of blood glucose. There are two major types of diabetes, type 1 and type 2. The graphs below show blood levels of glucose and insulin in three patients after each has consumed a sugary soft drink. Use the graphs to identify which patient is healthy, which has type 1 diabetes, and which has type 2 diabetes. Drag the labels to their appropriate locations above the graphs.

Patient A: Type 1 diabetes Patient B: Healthy Patient C: Type 2 diabetes In people with diabetes mellitus, the body is unable to maintain homeostasis of blood glucose. In type 1 diabetes, the immune system destroys most of the beta cells of the pancreas. Little or no insulin is produced. As a result, blood glucose levels remain elevated for a longer period than in healthy individuals. In type 2 diabetes, the pancreas produces sufficient insulin. However, the body's target cells do not respond to insulin effectively. As a result, blood glucose levels remain elevated for a longer period than in healthy individuals. Because glucose levels remain high, the pancreas continues to release insulin -- this is why insulin levels are also higher than in healthy individuals. Chronic disruption of glucose homeostasis has serious effects, particularly for the heart, blood vessels, kidneys, and eyes. In the U.S., diabetes is a major cause of blindness and the seventh most common cause of death.

Choose the correct statement from the list below. 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 Mechanical digestion of proteins is more important than chemical digestion. 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. The building blocks of proteins are amino acids.

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

Salivary glands. The salivary glands are not part of the alimentary canal but contribute digestive enzymes to break down food in the mouth.

Note that the subject mice gained much more mass in pairing (b) than in pairing (a), whereas the subject mice in pairing (d) lost mass. Which of these hypotheses could explain the result for pairing (d)? The db+ gene product is the receptor for the ob+ satiety factor; the db mutant in pairing (d) cannot receive this receptor through the circulation and therefore overproduces the ob+ satiety factor. The db+ gene product is the receptor for the ob+ satiety factor; the db mutant in pairing (d) receives this receptor from its partner through their shared circulatory system. The db+ gene product is another satiety factor; it suppresses appetite like the satiety factor encoded by the ob+ gene.

The db+ gene product is the receptor for the ob+ satiety factor; the db mutant in pairing (d) cannot receive this receptor through the circulation and therefore overproduces the ob+ satiety factor. Without receptors for the ob+ satiety factor, the db mutant mice in pairing (d) did not experience the negative feedback that normally slows down production of the satiety factor. Consequently, they overproduced the ob+ satiety factor, which caused the subject mice in pairing (d) to lose their appetites.

Based on the data shown in the table, which of the following is a reasonable conclusion about the wild-type gene products? The db+ gene product had no effect on the results of the experiment. The ob+ gene product circulated between both mice in a pair, even when only one mouse was wild-type for that gene. The ob+ gene product did not circulate to the mutant mice when they were paired with wild-type mice. The ob+ gene product had no effect on the results of the experiment.

The ob+ gene product circulated between both mice in a pair, even when only one mouse was wild-type for that gene.

Compare the result for pairing (b) with the result for pairing (c). What effect does the ob+ gene product appear to have on appetite? The ob+ gene product suppresses appetite. The ob+ gene product promotes appetite. The ob+ gene product neither promotes nor suppresses appetite.

The ob+ gene product suppresses appetite. The ob+ gene product appears to suppress appetite, which is why it is called a satiety factor. In pairings (b) and (c), the ob mutants gained much less mass when they were paired with wild-type mice than when they were paired with other ob mutants. This suggests that the ob+ gene product made by a wild-type mouse can circulate through the blood of an ob mutant.

In the animation, you saw that both high blood glucose levels and low blood glucose levels are stimuli that trigger specific responses by the body. These responses cause blood glucose levels to return to their normal range. In this activity, you will explore how this happens. Drag the labels to their appropriate locations on the diagram.

a. Beta cells of pancreas release insulin b. Body cells take up more glucose c. Liver takes up glucose and builds glycogen d. Blood glucose levels fall e. Alpha cells of pancreas release glucagon f. Liver breaks down glycogen and releases glucose g. Blood glucose levels rise Insulin and glucagon act together to maintain homeostasis of blood glucose levels. When blood glucose levels rise, insulin is released. Insulin causes the liver to take up glucose and convert it to glycogen. Insulin also causes most cells in the body to take up glucose. As a result, blood glucose returns to its normal range. When blood glucose levels fall, glucagon is released. Glucagon causes the liver to break down glycogen and release glucose into the blood. As a result, blood glucose returns to its normal range.

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

amino acids Proteins are composed of amino acids.

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 Fats are composed of glycerol and fatty acids.

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 The presence of fatty acids and amino acids in the stomach contents triggers the small intestine to secrete CCK. CCK then stimulates the gall bladder to release bile and the pancreas to secrete pancreatic enzymes.

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

pancreas ... bicarbonate The acidity of the stomach contents triggers the small intestine to secrete secretin, which in turn stimulates the pancreas to secrete bicarbonate to neutralize this acidity.

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

pancreas ... pancreatic enzymes The presence of fatty acids and amino acids in the stomach contents triggers the small intestine to secrete CCK. CCK then stimulates the pancreas to secrete enzymes that play a role in the digestion of these nutrients.

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

polysaccharide Starch is a carbohydrate composed of many monomers (many monosaccharide units).