Ap Biology Chapter 41 Vocabulary

Front 1

absorption

Back 1

The uptake of small nutrient molecules by an organism's own body; the third main stage of food processing, following digestion.

Front 2

acid chyme

Back 2

A mixture of recently swallowed food and gastric juice.

Front 3

alimentary canals

Back 3

A digestive tract consisting of a tube running between a mouth and an anus.

Front 4

aminopeptidase

Back 4

An enzyme found within the small intestine that splits off one amino acid at a time, beginning at the opposite end of the polypeptide containing a free carboxyl group

Front 5

appendix

Back 5

A small, fingerlike extension of the vertebrate cecum; contains a mass of white blood cells that contribute to immunity.

Front 6

bile

Back 6

A mixture of substances that is produced in the liver, stored in the gall bladder, and acts as a detergent to aid in the digestion and absorption of fats.

Front 7

bolus

Back 7

A lubricated ball of chewed food.

Front 8

bulk–feeder

Back 8

Animals that eat relatively large pieces of food.

Front 9

carboxypeptidase

Back 9

An enzyme found within the small intestine that splits off one amino acid at a time, beginning at the end of the polypeptide that has a free carboxyl group.

Front 10

carnivore

Back 10

An animal, such as a shark, hawk, or spider, that eats other animal

Front 11

cecum

Back 11

(plural, ceca) A blind outpocket of a hollow organ such as an intestine.

Front 12

cholecystokinin (CCK)

Back 12

A hormone released from the walls of the duodenum in response to the presence of amino acids or fatty acids.

Front 13

chylomicron

Back 13

Small intracellular globules composed of fats that are mixed with cholesterol and coated with special proteins.

Front 14

chymotrypsin

Back 14

An enzyme found in the duodenum. It is specific for peptide bonds adjacent to certain amino acids.

Front 15

colon

Back 15

The tubular portion of the vertebrate alimentary tract between the small intestine and the anus; functions mainly in water absorption and the formation of feces.

Front 16

complete digestive tract

Back 16

A digestive tube that runs between a mouth and an anus; also called alimentary canal. An incomplete digestive tract has only one opening.

Front 17

deposit–feeders

Back 17

A heterotroph, such as an earthworm, that eats its way through detritus, salvaging bits and pieces of decaying organic matter.

Front 18

digestion

Back 18

The process of breaking down food into molecules small enough for the body to absorb.

Front 19

dipeptidase

Back 19

An enzyme found attached to the intestinal lining. It splits small peptides.

Front 20

duodenum

Back 20

The first section of the small intestine, where acid chyme from the stomach mixes with digestive juices from the pancreas, liver, gallbladder, and gland cells of the intestinal wa

Front 21

elimination

Back 21

The passing of undigested material out of the digestive compartment.

Front 22

emulsification

Back 22

The process that keeps tiny fat droplets from coalescing.

Front 23

enterogastrones

Back 23

A category of hormones secreted by the wall of the duodenum.

Front 24

enteropeptidase

Back 24

An intestinal enzyme that directly or indirectly triggers activation of other enzymes within the intestinal lume

Front 25

epiglottis

Back 25

A cartilaginous flap that blocks the top of the windpipe, the glottis, during swallowing, which prevents the entry of food or fluid into the respiratory system.

Front 26

esophagus

Back 26

A channel that conducts food, by peristalsis, from the pharynx to the stomach.

Front 27

essential amino acids

Back 27

The amino acids that an animal cannot synthesize itself and must obtain from food. Eight amino acids are essential in the human adult.

Front 28

essential fatty acids

Back 28

Certain unsaturated fatty acids that animals cannot make.

Front 29

essential nutrients

Back 29

A chemical element that is required for a plant to grow from a seed and complete the life cycle, producing another generation of seeds.

Front 30

extracellular digestion

Back 30

The breakdown of food outside cells.

Front 31

feces

Back 31

The wastes of the digestive tract.

Front 32

fluid–feeders

Back 32

An animal that lives by sucking nutrient-rich fluids from another living organism.

Front 33

gallbladder

Back 33

An organ that stores bile and releases it as needed into the small intestine.

Front 34

gastric juice

Back 34

The collection of fluids secreted by the epithelium lining the stomach.

Front 35

gastrin

Back 35

A digestive hormone, secreted by the stomach, that stimulates the secretion of gastric juice.

Front 36

gastrovascular cavities

Back 36

An extensive pouch that serves as the site of extracellular digestion and a passageway to disperse materials throughout most of an animal's body

Front 37

hepatic portal vessel

Back 37

A large circulatory channel that conveys nutrient-laden blood from the small intestine to the liver, which regulates the blood's nutrient content

Front 38

herbivore

Back 38

A heterotrophic animal that eats plants.

Front 39

hydrolysis

Back 39

A chemical process that lyses, or splits, molecules by the addition of water; an essential process in digestion.

Front 40

ileum

Back 40

The last of three sections of the small intestine primarily involved in the absorption of nutrients and water.

Front 41

ingestion

Back 41

A heterotrophic mode of nutrition in which other organisms or detritus are eaten whole or in pieces.

Front 42

intracellular digestion

Back 42

The joining of food vacuoles and lysosomes to allow chemical digestion to occur within the cytoplasm of a cell.

Front 43

jejunum

Back 43

The middle section of the small intestine primarily involved in the absorption of nutrients and water.

Front 44

lacteal

Back 44

A tiny lymph vessel extending into the core of an intestinal villus and serving as the destination for absorbed chylomicrons.

Front 45

lipase

Back 45

An enzyme that hydrolyzes fat molecules in the intestinal lumen.

Front 46

liver

Back 46

The liver performs diverse functions such as producing bile, preparing nitrogenous wastes for disposal, and detoxifying poisonous chemicals in the blood.

Front 47

malnourished

Back 47

An animal whose diet is missing one or more essential nutrients.

Front 48

microvilli

Back 48

(plural, microvilli) One of many fine, fingerlike projections of the epithelial cells in the lumen of the small intestine that increase its surface area.

Front 49

mineral

Back 49

In nutrition, a chemical element other than hydrogen, oxygen, or nitrogen that an organism requires for proper body functioning.

Front 50

nuclease

Back 50

A team of enzymes that hydrolyze DNA and RNA into their component nucleotides.

Front 51

omnivore

Back 51

A heterotrophic animal that consumes both meat and plant material.

Front 52

overnourishment

Back 52

A diet that is chronically excessive in calories.

Front 53

pancreas

Back 53

A gland with dual functions: The nonendocrine portion secretes digestive enzymes and an alkaline solution into the small intestine via a duct; the endocrine portion secretes the hormones insulin and glucagon into the blood.

Front 54

pepsin

Back 54

An enzyme present in gastric juice that begins the hydrolysis of protein

Front 55

pepsinogen

Back 55

The inactive form of pepsin that is first secreted by specialized (chief) cells located in gastric pits of the stomach.

Front 56

peristalsis

Back 56

Rhythmic waves of contraction of smooth muscle that push food along the digestive tract.

Front 57

pyloric sphincter

Back 57

In the vertebrate digestive tract, a muscular ring that regulates the passage of food out of the stomach and into the small intestine.

Front 58

rectum

Back 58

The terminal portion of the large intestine where the feces are stored until they are eliminated.

Front 59

salivary amylase

Back 59

A salivary gland enzyme that hydrolyzes starch.

Front 60

salivary glands

Back 60

Exocrine glands associated with the oral cavity. The secretions of salivary glands contain substances to lubricate food, adhere together chewed pieces into a bolus, and begin the process of chemical digestion.

Front 61

secretion

Back 61

(1) The discharge of molecules synthesized by a cell. (2) In the vertebrate kidney, the discharge of wastes from the blood into the filtrate from the nephron tubules.

Front 62

small intestine

Back 62

The longest section of the alimentary canal. It is the principal site of the enzymatic hydrolysis of food macromolecules and the absorption of nutrients.

Front 63

sphincter

Back 63

A ringlike valve, consisting of modified muscles in a muscular tube, such as a digestive tract; closes off the tube like a drawstring.

Front 64

trypsin

Back 64

An enzyme found in the duodenum. It is specific for peptide bonds adjacent to certain amino acids.

Front 65

undernourishment

Back 65

A diet that is chronically deficient in calories.

Front 66

villi

Back 66

(singular, villus) (1) A fingerlike projection of the inner surface of the small intestine. (2) A fingerlike projection of the chorion of the mammalian placenta. Large numbers of villi increase the surface areas of these organs.

Front 67

vitamin

Back 67

An organic molecule required in the diet in very small amounts; vitamins serve primarily as coenzymes or parts of coenzymes.