Chapter 5 & 6

Question 1

Digestion

Answer 1

process by which food is broken down in the go tract to release nutrients in forms the body can absorb

Question 2

absorption

Answer 2

process by which nutrients are taken into cells that line the GI tract

Question 3

transport

Answer 3

movement of nutrients though the circulatory system from one area of the body to another

Question 4

metabolism

Answer 4

sum of the vast number of chemical changes in the cell that ultimately product the material that are essential for energy, tissue building and metabolic controls

Question 5

salivary amylase

Answer 5

starch-splitting enzyme in the mouth that is secreted by the salivary glands
commonly called ptyalin (spittle)

Question 6

chyme

Answer 6

semifluid food mass in the GI tract that is present after gastric digestion

Question 7

gastrin

Answer 7

• hormone that helps with gastric motility
• stimulates secretion of gastric acid by the parietal cells of the stomach
• stimulates the chief cells to secrete pepsinogen

Question 8

pepsin

Answer 8

main gastric enzyme specific to proteins

• begins breaking large protein molecules into shorter-chain polypeptides
• gastric hydrochloric acid is necessary for its activation.

Question 9

pancreatic amylase

Answer 9

major starch-splitting enzyme

• secreted by the pancreas
• acts in the small intestine

Question 10

trypsin

Answer 10

protein-splitting enzyme

• produced in the pancreas
• released into the small intestine
• inactive precursor trypsinogen activated by enterokinase

Question 11

chymotripsin

Answer 11

protein-splitting milk curdling pancreatic enzymes

• activated in the small intestine from the precursor chymotrypsinogen
• breaks specific amino acid peptide links of protein

Question 12

carboxypeptidase

Answer 12

protein enzyme that splits off the carboxyl group (-COOH) at the end of peptide chains

Question 13

pancreatic lipase

Answer 13

major fat splitting enzyme

• produced by the pancreas
• secreted into the small intestine to digest fat

Question 14

mucosal folds

Answer 14

large visible folds of the mucous lining of the small intestine that increase the absorbing surface area

Question 15

villi

Answer 15

small protrusions from the surface membrane

• fingerlike projections that cover the mucosal surfaces of the small intestine
• further increase the absorbing surface area
• visible through a regular microscope

Question 16

microvilli

Answer 16

extremely small hair like projections

• cover all villi on surface of small intestine
• greatly extend the total absorbing surface area
• visible through an electron microscope

Question 17

catabolism

Answer 17

metabolic process of breaking down large substances to yield smaller building blocks

Question 18

anabolism

Answer 18

metabolic process of building large substances from smaller parts
- opposite of catabolism

Question 19

glycogenesis

Answer 19

anabolic process of creating stored glycogen from glucose

Question 20

lipogenesis

Answer 20

anabolic process of forming fat

Question 21

adipose tissue

Answer 21

storage site for excess fat

Question 22

gluconeogenesis

Answer 22

formation of glucose from non-carbohydrate substances (ex: amino acids)

Question 23

thermic effect of food

Answer 23

an increase in energy expenditure caused by the activities of digestion, absorption, transport, and storage of ingested food

• a meal that consists of a usual mixture of carbs, protein, and fat increases the energy expenditure equivalent to approximately 10% of the foods energy content
• ex: 300 kcal pizza would elicit an energy expenditure of 30 kcal to digest the food

Question 24

calorie

Answer 24

a measure of heat

• the energy necessary to do work is measured as the amount of heat produced by the body’s work
• the energy value of a food is expressed as the number of kilocalories that a specified portion of the food will yield when it is oxidized in the body

Question 25

resting energy expenditure (REE)

Answer 25

the amount of energy (in kcal) needed by the body for the maintenance of life at rest over a 24 hour period - often used interchangeably with the term basal energy expenditure, but in actuality it is slightly higher

Question 26

basal energy expenditure (BEE)

Answer 26

the amount of energy (in kcal) needed by the body for maintenance of life when a person is at complete digestive, physical, mental, thermal, and emotion rest - ex: 10-12 hours after eating and 12-18 hours after physical activity - measured immediately upon waking

Question 27

thyroxine (T4)

Answer 27

- thyroid prohormone - the active hormone is T3 - the major controller of basal metabolic rate

Question 28

adaptive thermogenesis

Answer 28

an adjustment to heat production in response to changing environmental influence (external temperature, diet, etc.)

Question 29

what makes up the total energy requirement

Answer 29

RMR, physical activities, and thermic effect of food

Question 30

maintenance of daily energy balance

Answer 30

food energy intake must match body energy output