Chapter 29: Nutrition And Digestion

Front 1

What are nutrients? What 5 categories do they fit into?

Back 1

Nutrients: substances that must be supplied in the diet.

lipids, carbohydrates, proteins, minerals, vitamins

Front 2

What are the primary sources of energy?

Back 2

Carbs and Fats

Front 3

Describe 3 types of lipids.

Back 3

1. fat/triglycerides: source of energy
2. phospholipids: make up cell membranes
3. cholesterol: makes up sex hormones and bile.

Front 4

What are essential fatty acids? What are essential amino acids?

Back 4

Must acquire lipids/amino acids from the diet because are not synthesized naturally in the body

Front 5

What is the quickest source of energy? How is this source stored in humans?

Back 5

Carbohydrates, including sugars and starches!

Stored in form of glycogen: a polysaccharide that is a chain of glucose molecules

Front 6

define urea

Back 6

the waste product of protein breakdown, which is filtered from the blood by the kidneys

Front 7

List some functions of proteins.

Back 7

- composed of amino acids that help make hormones, other amino acids, and new proteins
- act as enzymes
- antibodies
- muscle proteins

Front 8

Describe what occurs during a protein deficiency.

Back 8

protein deficiencies can result in a lot of scary conditions, like kwashiorkor. muscles are wasted due to a lack of protein.

Front 9

define minerals and describe iron.

Back 9

include various elements and inorganic molecules that must be obtained through the diet.

Iron: produces hemoglobin... a lack of can lead to anemia

Front 10

define vitamins.

Back 10

group of organic compounds that must be obtained through diet

Front 11

Vitamin C (water soluble vitamins?)

Back 11

is an antioxidant. It combines with free radicals that would usually damage DNA to limit their effects. (can cause scruvy)

is water soluble, which means..
- dissolves in blood plasma
- not much is stored in body
- works with enzymes

Front 12

Vitamin D (fat soluble vitamin?)

Back 12

promotes bone growth and increases calcium absorption. (can cause rickets)

is fat soluble which means...
- can be stored in fat and can accumulate over time

Front 13

Vitamin K (fat soluble?)

Back 13

regulates blood clotting.

Front 14

Digestion systems must accomplish....

Back 14

ingestion, mechanical breakdown, chemical breakdown, absorption, elimination

Front 15

Define intracellular digestion (sponges)

Back 15

: digestion occurs within individual cells
1. once food is englufed, food is enclosed in a food vacuole.
2. food vacuole fuses with digestive enzymes called lysosomes.
3. food is broken down

Front 16

define extracellular digestion

Back 16

larger, more complex organisms evolved a chamber where food could be broken down by enzymes OUTSIDE of the cells

Front 17

Describe the gastovascular cavity in Hydras. Why is this still a very simple digestive system?

Back 17

: digestive sac with a SINGLE OPENING, therefore both food is ingested and waste is ejected here


Because of the single opening, simple sac digestive systems can only process one meal at a time

Front 18

describe the tubular digestive system in earthworms.

Back 18

- mouth
- pharynx (connects mouth to esophagus)
- esophagus
- crop - storage organ tht collects food
- gizzard- where food is ground
- intestine - enzymes break down
- anus

Front 19

What are ruminant animals?

Back 19

Have a special digestive system in order to break down the cellulose in the food that they eat
(microorganisms produce cellulase)
- herbivore intest. are longer because need more time for absorption

Front 20

The Mouth: SALIVARY GLANDS

Back 20

- mechanical breakdown begins with the teeth
- 3 salivary glands pour out saliva, which contains amylase (breaks down starches into dissaccharides)
-lubricates food, carries bacteria killing enzyme to fight infection

Front 21

The Mouth: TOUNGE, PHARYNX

Back 21

- tongue pushes food into the pharynx, which connects to the esophagus

Front 22

(LARYNX, EPIGLOTTIS)

Back 22

- larynx: connects nose/mouth to trachea
epiglottis: flap of tissue that blocks of respiratory passages so food is directed into esophagus, not trachea.

Front 23

The Esophagus

Back 23

- Swallowing forces food into a muscular tube called the esophagus

- The esophagus forms waves of muscular contraction (peristalsis) that carry food to the stomach

Front 24

The Stomach and Pyloric Sphincter

Back 24

stomach: expandable muscular sac
pyloric: ring of muscle that separates the stomach from the small intestine; also regulates the passage of the food into small intest

Front 25

What are the stomach's 3 major functions?

Back 25

1. store food; release to small intestine
2. mechanical breakdown: muscular walls contract and churn food
3. chemical breakdown: there are glands in stomach that secrete enzymes and hormones and such

Front 26

What are the stomach's secretions?

Back 26

- gastrin: (hormone) stimulates the production of hydrochloric acid
- HCI: makes fluid in stomach acidic, allows pepsin to activate
- pepsin (a type of protease): breaks proteins into shorter chains
- mucus: protects stomach wall from acid

Front 27

define chyme

Back 27

: mix partially digested food particles + stomach secretions.
- highly acidic
- goes through the pyloric sphincter and into the small inestine

Front 28

The Small Intestine: LIVER AND GALLBLADDER

Back 28

- stores fats and carbs (in glycogen) for energy, regulates blood glucose levels, stores iron, detoxifies harmful
- produces BILE, stored in gallbladder

Front 29

define bile

Back 29

: mixture of bile salts, water, other salts, cholesterol

- bile salts breaks down fat in the chyme by dispersing them into small particles that enzymes (lipases) can act on

Front 30

The Small Intestine: PANCREAS

Back 30

- secretes pancreatic juice
- made up of water, sodium bicarbonate (buffer: neutralizes the acidic chyme), and digestive enzymesssss such as *amylase, lipase, protease

Front 31

The Small Intestine: Absorption

Back 31

most absorption occurs in the small intestine.
- fingerlike projections, VILLI and stemming from that MICROVILLI, create more surface area
- fats = absorbed by lacteal on each villus
- water, monosaccharides, amino acids, vitamins, minerals.... absorbed by small intestine

Front 32

define segmentation movements

Back 32

: contractions in the small intestine that slosh chyme back and forth
- brings nutrients into the surface of the intestine where they can easily be absorbed

Front 33

The Large Intestine

Back 33

colon: most of length
rectum: terminal end
A mix of water, undigested nutrients, and fiber enters the large intestine

- contains bacteria that consume the unabsorbed nutrients

Front 34

The Large Intestine: FECES

Back 34

: semi solid remnants that consist of indigestible wastes and dead bodies of bacteria
- peristalsis moves the feces out

Front 35

How does the nervous system impact the digestive system?

Back 35

1. sceretion of saliva
2. secretion of HCI and gastrin
3. acid secretion is regulated by negative feedback