Nutrition and Digestion

Question 1

What are the dietary modes?

Answer 1

Carnivores: eat other animals
Herbivores: eat autotrophs (plants)
Omnivores: eat both animals and plants
Detritivores: eat dead/decaying matter

Question 2

What type of eaters are most animals?

Answer 2

opportunistic

Question 3

What must diet satisfy for?

Answer 3

energy, atoms (carbon and nitrogen), and essential nutrients

Question 4

What are essential nutrients?

Answer 4

cannot be made by cells, but needed for life
essential amino acids
essential fatty acids
vitamins
minerals

Question 5

What is undernourishment?

Answer 5

diet provides less energy than needed for maintenance of body and functions (starvation)

Question 6

What is malnourishment?

Answer 6

long-term lack of one or more essential nutrients from the diet, leading to deformity/disease

Question 7

What are the four stages of food processing?

Answer 7

ingestion, digestion, absorption, and elimination

Question 8

What are the four types of feeders?

Answer 8

suspension (filter): pushing, sucking, flowing water through structures

substrate: live on or in their food source
fluid: often parasites that suck nutrient rick liquids
bulk: have jaws and test to eat large chunks and are swallowed

Question 9

Describe test in mammals/vertebrates.

Answer 9

types of dentition based diet species has adapted to
teeth vary in size, shape, and cutting surface
vary in number of different types

Question 10

What is digestion?

Answer 10

breaking down food into molecules small enough to later absorb

Question 11

What is mechanical digestion?

Answer 11

chewing breaks food into smaller pieces

Question 12

What is chemical digestion?

Answer 12

enzymatic hydrolysis splits molecule bonds

Question 13

What is intracellular digestion?

Answer 13

endocytosis into cells occurs before complete digestion

lysosomes fuse and form food vacuoles where particles are further broken down

Question 14

What is extracellular digestion?

Answer 14

completely digest food before absorption into cells

most animals do this though a simple gastrovascular cavity or complex alimentary canal

Question 15

What is the first stage of extracellular digestion?

Answer 15

mechanical digestion in the oral cavity through chewing
salivary glands begin chemical digestion with Amylase to lubricate food
tongue forms a bolus of food for swallowing

Question 16

What is the pharynx?

Answer 16

mammals have a junction between both the esophagus and windpipe (trachea) to the lungs

Question 17

How does swallowing occur?

Answer 17

sphincter releases that causes the epiglottis to block the trachea
bolus is move to the stomach via peristalsis from smooth muscle

Question 18

What is gastric juice?

Answer 18

hydrochloric acid: break up ECM and denature proteins

Pepsin: when large cellular components are exposed so proteins are digested into amino acids

Question 19

What are the three cell types of the gastric gland?

Answer 19

parietal cells: secrete H+ and Cl- into stomach
chief cells: secrete pepsinogen which becomes pepsin when mixed with HCl
mucous cells: secrete mucous to protect lining from gastric juice

Question 20

What are the three divisions of the small intestine?

Answer 20

duodenum
jejunum
ileum

Question 21

Describe the duodenum.

Answer 21

entry point for digestive enzymes
most digestion occurs here
makes its own digestive enzymes from the epithelial lining

Question 22

What is the pancreas?

Answer 22

sends lipases, proteases, and nuclease to breakdown fats, proteins, and nucleic acids

Question 23

What is the liver?

Answer 23

makes bile salts, which are first stored in the gallbladder, and are used to breakdown fats

Question 24

What part of small intestine perform the most absorption?

Answer 24

jejunum and ileum

Question 25

What are villi?

Answer 25

fingerlike layers of cells that extend into the intestinal space; have blood vessels for transport of nutrients throughout the body

Question 26

What are microvilli?

Answer 26

fingerlike cell membranes on individual cells that increase surface area and nutrient exchange

Question 27

Where does important absorption occur?

Answer 27

in the cesium and colon

Question 28

What is the cesium?

Answer 28

aids in plant fermentation so more material can be extracted

Question 29

What is the colon?

Answer 29

remain sections along the large intestine that play a critical role in absorbing water

Question 30

Where in undigested material expelled?

Answer 30

through the rectum and anus

Question 31

What are symbiotic bacteria?

Answer 31

bacteria that lives on/in us
food is delivered, shelter provided
produces nutrients not normally available to the host

Question 32

What is different about the gut length of herbivores?

Answer 32

longer small intestine and cecum to allow for longer time to digest/absorb plant nutrients

Question 33

What are ruminates?

Answer 33

have a special forget, a Rumen, where extra fermenting by symbiotic bacteria can occur