exam 3 homework questions

What is the main component of gastric juice? a. inactive pepsin b. water c. amylase d. hydrochloric acid e. bile

b.

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

b. 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. a. True b. False

b. 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.

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

b. Fat digestion is not complete until pancreatic lipases finalize fat digestion in the small intestine.

Your small intestine can absorb ____ without its being further digested. a. nucleic acid b. fructose c. protein d. fat e. starch

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

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. a. True b. False

b. 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.

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

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

Starch is a type of _____. a. disaccharide b. monosaccharide c. nucleotide d. fatty acid e. polysaccharide

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

When digested, fats are broken down into _____. a. glycerol only b. fatty acids only c. monosaccharides d. amino acids e. both glycerol and fatty acids

e. Fats are composed of glycerol and fatty acids.

What is the alimentary canal?

The gastrointestinal tract; an organ system within humans and other animals which takes in food, digests it to extract and absorb energy and nutrients, and expels the remaining waste as feces.

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

a.

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

a. 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.

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

c. An alimentary canal has two openings, and food moves through it unidirectionally. In contrast, a gastrovascular cavity has only one opening.

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

c. The building blocks of proteins are amino acids.

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

d.

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

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

When digested, proteins are broken down into _____. a. glycerol only b. fatty acids only c. monosaccharides d. amino acids e. both glycerol and fatty acids

d. Proteins are composed of amino acids.

Starch can be broken down into the disaccharide known as _____. a. glucose b. lactose c. sucrose d. maltose e. fructose

d. Starch is composed of many maltose units.

Parts of the alimentary canal (9)

mouth, oral cavity, teeth, oesophagus, pharynx, stomach, small intestine, large intestine, and anus.