Digestion

Question 1

What is digestion

Answer 1

mechanical and chemical breaking down of food into particles small enough for the body to absorb

Question 2

What is absorption

Answer 2

when the small molecules pass from the lumen of the gut into the blood or lymph

Question 3

what is the difference between chemical and mechanical digestion

Answer 3

mechanical= the physical breaking down of injested food by things like teeth or stomach thurning
Chemical= the use of the bodys hydrolytic enzymes and HCl to break down food

Question 4

What is a hydrolytic enzyme

Answer 4

an enzyme that breaks down macromolecules by adding water

Question 5

what is the enzyme in saliva

Answer 5

Salivary amylase

Question 6

What is a substrate of salivary amylase and what are the products

Answer 6

substrate is starch
products are maltose
(starch+h2o=maltose)

Question 7

What is peristalsis

Answer 7

rhythmic waves of muscle contractions that pushes food down the esophagus

Question 8

What are 3 functions of the stomach

Answer 8

1) stores food until small intestine is ready for another small quantity
2) churns the food with its muscles mixing it with gastric secretions
3) produces gastric juices containing HCl

Question 9

what does HCl do in the stomach

Answer 9

kills bacteria
breaks down connective tissue
creates an acidic environment which activates the digestive enzyme pepsin

Question 10

what does pepsin do in the stomach

Answer 10

breaks down proteins into peptides

Question 11

How is pepsin made

Answer 11

gastric juices produced by gastric gland in stomach consist of HCl, pepsinogen, and water. The HCl mixes with pepsinogen to make the active enzyme pepsin

Question 12

What is the Pharynx

Answer 12

region between mouth and esophagus where swallowing occurs

Question 13

what does the epiglottis do

Answer 13

is a flap of tissue that covers the opening to the trachea when swallowing

Question 14

what is the cardiac sphincter

Answer 14

circular muscle that can open and close the control movement of food into stomach from esophagus.

Question 15

What is the esophagus

Answer 15

a long muscular tube that uses perstalsis to send food from mouth to stomach

Question 16

what is pepsinogen

Answer 16

a precursor molecule of gastric juice that forms pepsin when mixed with HCl

Question 17

Where does the majority of digestion take place

Answer 17

In the duodenum

Question 18

3 parts of the small intestine are

Answer 18

duodenum
jejenum
ilium

Question 19

what controls the flow of material into the duodenum

Answer 19

pyloric sphincter at bottom of stomach, opens periodically to empty some chyme into duodenum

Question 20

the material the enters the duodenum is called

Answer 20

chyme

Question 21

what is the funtion of the duodenum

Answer 21

secretions from liver (bile) and pancreas break down fats and peptides

Question 22

what does the liver produce for the duodenum

Answer 22

bile

Question 23

what do bile salts do

Answer 23

emulsifying agent for fats to break up

Question 24

what sodium compound does pancreatic juice contain

Answer 24

NaHCO3

Question 25

what does NaHCO3 do

Answer 25

Neutralize acid chyme and makes small intestine pH basic

Question 26

what 3 enzymes do pancreatic juice contain

Answer 26

Pancreatic amylase trypsin Lipase

Question 27

what is the function of pancreatic amylase

Answer 27

digest starch to maltose

Question 28

what is the function of trypsin

Answer 28

digests pepsin to peptides

Question 29

what is the function of lipase

Answer 29

digests fat to fatty acids and glycerol

Question 30

what are two important intestinal juice enzymes and their funtions are

Answer 30

Peptidases: degest pepsin to amino acids Maltose: digests maltose to glucose

Question 31

where does absorption take place

Answer 31

across each villus into blood and lymph vessels

Question 32

is absorption passive? what does it require?

Answer 32

-can happen passively or when activates -active transport requires ATP

Question 33

Where do sugars and amino acids go when absorbed

Answer 33

into the blood via capillaries

Question 34

where do glycerol and fatty acids go when absorbed

Answer 34

recombined into lipids and enter lacteal (leads to lymph system)

Question 35

what is the function of the hepatic portal

Answer 35

blood vessels from velli merge to hepatic portal vein which carries nutrients to the liver

Question 36

what are 6 functions of the liver

Answer 36

-produce bile -keeps blood glucose constant -detoxifies blood -destroys old RBCs produces urea (deamination of AAs) -makes blood protiens from AAs

Question 37

what is the main different function of the large intestine from the small

Answer 37

the large does not absorb nutrients like the small but instead absorbs water.

Question 38

what is the main bacteria in the large intestine

Answer 38

e.coli

Question 39

where is gastrin released from and why

Answer 39

from the gastric gland in upper stomach it perfroms secretion of gastric juices (pepsinogen and HCl)

Question 40

what are carbs broken into

Answer 40

glucose

Question 41

what are fats broken into

Answer 41

glycerol+fatty acids

Question 42

what are proteins broken into

Answer 42

AAs

Question 43

what are the two sphincters at the top and bottom of the stomach

Answer 43

pylroic sphincter (bottom) cardiac sphincter (top)

Question 44

what substance does the stomach digest

Answer 44

proteins (breaks them down into smaller chains of amino acids (peptides))

Question 45

what are 2 pancreatic secretions

Answer 45

pancreatic juice Insulin and glucagon

Question 46

what is the function of e coli in the large intestine.

Answer 46

break donw indigestable foods, produces vitamins, AAs and other growth factors that get absorbed by the colon

Question 47

what blood vessels do products of digestion enter

Answer 47

most of the digestive process enters the capillary system, fats and fat soluble nutrients diffuse into the lymphatic vessels

Question 48

what problems would occur if the liver stopped functioning

Answer 48

blood woulf become toxic fats cant be broken down (no bile) blood glucose would not be constant plasma protien + cholesterol would not be produced

Question 49

Carb digestion

Answer 49

Mouth: salivary amylose breaks down starch to maltose -Pancreatic amylose does the same -Intestinal glands produce maltose that digests maltose to glucose -glucose absorbed by blood vessels

Question 50

protein digestion

Answer 50

-pepsin in stomach breaks down protein into polypeptide -trypsin breaks polypeptide into a peptide -peptidases from intestinal land break peptides into amino acids -AAs are absorbed into bloodstream thru villi

Question 51

Fat digestion

Answer 51

-enters duodenum where bile salts break fat down into droplets -fat droplets are broken into glycerol and fatty acids by lipase in pancreatic juice -glycerol and fatty acids are absorbed by lacteals and enter lymphatic system

Question 52

Salivary amylase breaks down what to what

Answer 52

starch to maltose

Question 53

pepsin breaks down what to what

Answer 53

proteins to peptides

Question 54

peptidase breaks down what to what

Answer 54

peptides to amino acids

Question 55

maltose breaks down what to what

Answer 55

maltose to glucose

Question 56

lipase breaks down what to what

Answer 56

fats to glycerol/fatty acids

Question 57

trypsin breaks down what to what

Answer 57

polypeptides to peptides

Question 58

pancreatic amylose breaks down what to what

Answer 58

starch to maltose

Question 59

What part covers the trachea when swallowing

Answer 59

epiglottis

Question 60

What is the movement of the esophagus when swallowing called

Answer 60

peristalsis