lec 8 pt2 nutrition and digestion

Question 1

living organisms require ____ as nutrients

Answer 1

elements

Question 2

what are macronutrients?

Answer 2

elements needed in large amounts

Question 3

which 3 macronutrients make up 93% of our weight?

Answer 3

C, H, O

Question 4

what are micronutrients? whats an example?

Answer 4

tiny amts necessary for life
eg. vitamins

Question 5

which element is needed in a small amount to be used to make hormones?

Answer 5

iodine

Question 6

what are 3 main categories of human dietary requirements?

Answer 6

-carbohydrates
-fats (lipids)
-protien

Question 7

explain why we need each of the 3 categories of human dietary requirements?

Answer 7

carbs:
-source of energy+carbon

fats:
-concentrated form of energy
-essential fats: required to make certain compounds

protein:
-source of amino acids
-b/c we cant make all AA

Question 8

what are essential amino acids?

Answer 8

amino acids we MUST obtain from food

Question 9

how to animals obtain nutrients?

Answer 9

digesting food in order to absorb necessary molecules

Question 10

one way system that carries food from mouth to anus

Answer 10

digestive system (gut)

Question 11

what are two roles of saliva?

Answer 11

-moistens food to aid in digestion
-breaks starch–> sugar w/ enzyme amylase

Question 12

what is the route food takes after leaving the mouth?

Answer 12

esophagus–> stomach–>small intestine–>colon–> anus

Question 13

once food reaches the stomach, what does the stomach do?

Answer 13

mixes food with acid + stores it

Question 14

where does food go after the stomach? what happens here?

Answer 14

small intestine

breaks down macromolecules for easy absorption

-small intestine’s epithelial cells absorb

Question 15

removes additional water and nutrients from food

Answer 15

colon/large intestine

Question 16

what happens after food passes through the colon?

Answer 16

food becomes feces

expelled thru anus

Question 17

the animal digestive system involves ______, ________ and waste.

Answer 17

breakdown, absorption

Question 18

specialized epithelial cells in the stomach secrete…?

Answer 18

HCl- hydrochloric acid

Question 19

what is the role of hydrochloric acid in the stomach?

Answer 19

-kills most microbes present in food
-breaks down extra-cellular matrix of food

Question 20

what is the purpose of mucous in the stomach? where is it produced?

Answer 20

-protects epithelial cells from HCl (acid)
-secreted from epithelial cells

Question 21

the stomach grinds food by….?

Answer 21

peristalsis: muscle contraction

Question 22

what is peristalsis?

Answer 22

muscle-driven movement of the gut

Question 23

what are proteases in the stomach? what is an important protease? where are they produced?

Answer 23

enzymes secreted by epithelial cells

Pepsin: breaks down protein

Question 24

what is the role of epithelial cells in the small intestine?

Answer 24

-secrete digestive enzymes
-absorb nutrients thru active transport

Question 25

what is the pancreas?

Answer 25

source of digestive enzymes

Question 26

what are 3 important digestive enzymes from the pancreas? what do they do?

Answer 26

lipase- breaks down fats

protease- breaks down protiens

amylase- breaks down carbs

Question 27

what is bile? where is it produced? where is it stored?

Answer 27

liquid that emulsifies lipids, increases efficiency of lipase

produced in liver
stored in gallbladder

Question 28

explain how the anatomy of the small intestine makes it the ultimate absorber

Answer 28

cavity lined with villi (finger-like projections of epithelial cells)

villi increase # of epithelial cells, therefore increasing absorption

villi kinda look like a microfiber duster

Question 29

why must food be broken down by enzymes during the digestion process?

Answer 29

in order to enter epithelial cells

Question 30

what occurs in the colon(large intestine) when it receives digested food?

Answer 30

-mostly water and some nutrients are absorbed
-food becomes feces

Question 31

the bacteria that heavily colonize the colon are called? what are two functions of this bacteria?

Answer 31

the normal flora

-produces certain vitamins (K)
-repels+inhibits pathogenic (harmful) bacteria

Question 32

the human digestive system is regulated by…?

Answer 32

hormones

Question 33

what is a common example of missing enzymes we see?

Answer 33

lack of lactase

causes lactosis/ lactose intolerance

Question 34

what is one enzyme that all animals are missing? what does it cause?

Answer 34

lack cellulase

cant digest cellulose so we don’t get much energy from plants

Question 35

how are herbivores able to survive off of plants if they lack cellulase?

Answer 35

intestinal microorganisms (bacteria, fungi, protists)
digest cellulose, release glucose

Question 36

filtering unit of the kidney

Answer 36

nephron

Question 37

what does the hormone gastrin do?

Answer 37

causes stomach to produce acid

Question 38

what is the role of secretin?

Answer 38

causes pancreas to send out digestive juice

stomach-pepsin
liver-bile

Question 39

hormone produced in the stomach and upper intestine when food is absent, stimulates appetite.

Answer 39

ghrelin

Question 40

produced in the GI tract when food is present,
inhibits appetite

Answer 40

peptide YY