Chapter 1: Intake: Gastrointestinal Digestion, Absorption, and Excretion of Nutrients

Question 1

pancreatic amylase

Answer 1

an enzyme produced in the pancreas that helps in the digestion of starches

Question 2

salivary amylase

Answer 2

an enzyme produced in the salivary glands that helps in the digestion of starches

Question 3

brush border membrane

Answer 3

the microvilli covered surface of simple cuboidal epithelium and simple columnar epithelium cells found in certain locations of the body. Brush border membranes are found where absorption takes place. Ex: small intestine and kidneys

Question 4

chelation

Answer 4

formation of multiple coordination bonds between organic molecules and a transition metal ion leading to sequestration of the metal

Question 5

cholecystokinin (CCK)

Answer 5

a hormone which is secreted by cells in the duodenum and stimulates the release of bile into the intestine and the secretion of enzymes by the pancreas.

Question 6

chyme

Answer 6

the pulpy acidic fluid which passes from the stomach to the small intestine, consisting of gastric juices and partly digested food.

Question 7

colonic salvage

Answer 7

Fermentation of malabsorbed carbohydrate and fiber by colonic microbes

Question 8

crypts

Answer 8

anatomical structures that are narrow but deep invaginations into a larger structure

Question 9

facilitated diffusion

Answer 9

a form of facilitated transport involving the passive movement of molecules along their concentration gradient, guided by the presence of another molecule – usually an integral membrane protein forming a pore or channel. No energy is needed for this type of transport

Question 10

passive diffusion

Answer 10

a process by which an ion or molecule passes through a cell wall via a concentration gradient, or from an area of high concentration to an area of low concentration. No energy is needed for this type of transport

Question 11

dysbiosis

Answer 11

an imbalance between the types of organism present in a person’s natural microflora, especially that of the gut, thought to contribute to a range of conditions of ill health.

Question 12

enterocyte

Answer 12

a cell of the intestinal lining

Question 13

enterohepatic circulation

Answer 13

Circulation of substances such as bile salts, which are absorbed from the intestine and carried to the liver, where they are secreted into the bile and again enter the intestine.

Question 14

enterokinase

Answer 14

an enzyme especially of the duodenal mucosa that activates trypsinogen by converting it to trypsin

Question 15

enzymatic hydrolysis

Answer 15

A catalytic decomposition of a chemical compound by reaction with water, such as the conversion of cellulosic materials into fermentable sugars by the addition of specific enzymes

Question 16

epithelial cells

Answer 16

cells that line the surfaces of organs in the body and function as a protective barrier. Epithelial cells are often associated with the skin (the epidermis). … Epithelial cells form the tissue that lines the surfaces of organs and cavities in the body.

Question 17

gastrin

Answer 17

a hormone which stimulates secretion of gastric juice and is secreted into the bloodstream by the stomach wall in response to the presence of food.

Question 18

ghrelin

Answer 18

a 28-amino-acid peptide hormone that is secreted primarily by stomach cells with lesser amounts secreted by other cells (as of the pancreas) and acts to stimulate appetite and the secretion of growth hormone

Question 19

glucagon-like peptide 2 (GLP-2)

Answer 19

a hormone secreted from the distal GIT that increases intestinal surface area and enhances nutrient processing capacity

Question 20

gut-brain axis

Answer 20

bidirectional communication between the central and the enteric nervous system, linking emotional and cognitive centers of the brain with peripheral intestinal functions.

Question 21

isomaltase

Answer 21

is an enzyme that breaks the bonds linking saccharides, which cannot be broken by amylase or maltase. It digests polysaccharides at the alpha 1-6 linkages.

Question 22

lactase

Answer 22

an enzyme that catalyzes the hydrolysis of lactose to glucose and galactose.

Question 23

gastric lipase

Answer 23

is the lipase that is responsible for initiating the digestion of dietary fats in the stomach

Question 24

pancreatic lipase

Answer 24

A pancreatic enzyme that splits dietary fats by hydrolyzing triacyglycerol substrates

Question 25

salivary lipase

Answer 25

The enzyme, released into the mouth along with the saliva, catalyzes the first reaction in the digestion of dietary lipid, with diglycerides being the primary reaction product. AKA lingual lipase

Question 26

lipolytic enzymes

Answer 26

An enzyme that catalyzes the hydrolysis of fats

Question 27

maltase

Answer 27

an enzyme, present in saliva and pancreatic juice, that catalyzes the breakdown of maltose and similar sugars to form glucose.

Question 28

micelle

Answer 28

an aggregate of molecules in a colloidal solution, such as those formed by detergents.

Question 29

microbiome

Answer 29

the microorganisms in a particular environment (including the body or a part of the body)

Question 30

microbiota

Answer 30

the microorganisms of a particular site, habitat, or geological period.

Question 31

microvilli

Answer 31

a microscopic projection of a tissue, cell, or cell organelle especially : any of the fingerlike outward projections of some cell surfaces

Question 32

motilin

Answer 32

a polypeptide hormone secreted by the small intestine that increases gastrointestinal motility and stimulates the production of pepsin

Question 33

mucosa

Answer 33

a membrane rich in mucous glands. specifically : one that lines body cavities and passages (as of the gastrointestinal or respiratory tract) which communicate directly or indirectly with the outside of the body

Question 34

parietal cells

Answer 34

an oxyntic (acid-secreting) cell of the stomach wall.

Question 35

pepsin

Answer 35

the chief digestive enzyme in the stomach, which breaks down proteins into polypeptides.

Question 36

peristalsis

Answer 36

the involuntary constriction and relaxation of the muscles of the intestine or another canal, creating wave-like movements that push the contents of the canal forward.

Question 37

prebiotic

Answer 37

a nondigestible food ingredient that promotes the growth of beneficial microorganisms in the intestines.

Question 38

probiotic

Answer 38

live microorganisms that are intended to have health benefits when consumed or applied to the body

Question 39

proteolytic enzymes

Answer 39

a group of enzymes that break the long chainlike molecules of proteins into shorter fragments (peptides) and eventually into their components, amino acids. AKA protease, proteinase, or peptidase

Question 40

secretin

Answer 40

a hormone released into the bloodstream by the duodenum (especially in response to acidity) to stimulate secretion by the liver and pancreas.

Question 41

segmentation

Answer 41

alternating contractions and relaxations of non-adjacent segments of the intestine that move food forward and backward, breaking it apart and mixing it with digestive juices

Question 42

somatostatin

Answer 42

a hormone secreted in the pancreas and pituitary gland that inhibits gastric secretion and somatotropin release.

Question 43

sucrase

Answer 43

an enzyme present in certain plant and animal tissues that catalyzes the hydrolysis of sucrose into glucose and fructose

Question 44

synbiotic

Answer 44

mixture of probiotics and prebiotics that beneficially affects the host by improving the survival and activity of beneficial microorganisms in the gut

Question 45

active transport

Answer 45

the movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy.

Question 46

passive transport

Answer 46

a process by which an ion or molecule passes through a cell wall via a concentration gradient, or from an area of high concentration to an area of low concentration

Question 47

trypsin

Answer 47

a digestive enzyme that breaks down proteins in the small intestine. It is secreted by the pancreas in an inactive form, trypsinogen.

Question 48

trypsinogen

Answer 48

an inactive substance secreted by the pancreas, from which the digestive enzyme trypsin is formed in the duodenum.

Question 49

unstirred water layer (UWL)

Answer 49

the slightly acidic and watery plate that forms a boundary between the intestinal lumen and the brush border membranes, the lipids detach from the micelles

Question 50

villus

Answer 50

any of the fingerlike or threadlike projections from the surface of certain membranous structures, typically serving to increase surface area and facilitate the passage of fluid or nutrients.