Biology - Ch 11 - Digestion

Front 1

What is heterotrophic?

Back 1

Unable to synthesize own nutrients

Front 2

What is intracellular digestion?

Back 2

Occurs within cell, membrane-bound vesicles

Front 3

What is extracellular digestion?

Back 3

Digestion that occurs outside of cell, in lumen or tract

Front 4

In unicellular organisms, how is food captured?

Back 4

Primarily by phagocytosis

Front 5

How does digestion occur in simple unicellular organisms?

Back 5

Food vacules that have been phagocytosed are approached by lysosomes that contain digestive enzymes

Digestive enzymes released into cell

Simpler molecules are then released into cytoplasm

Unusable products are eliminated from vacuole

Front 6

In paramecium, how does ingestion and digestion occur?

Back 6

Cilia sweep food into oral groove and cytopharynx

Food vacuole forms

Enzymes secreted into cell

Front 7

What does chewing do?

Back 7

Increases surface area for enzymes to act upon

Front 8

How does chemical breakdown of molecules occur?

Back 8

Enzymatic hydrolysis

Front 9

How do cnidarians digest food?

Back 9

Hydra use intracellular and extracellular digestion

Tentacles bring food to mouth and release food into cup-like sac

Endodermal cells lining gastrovascular cavity release digestive enzymes into cavity

Digestion occurs primarily outside of cell

Undigested food is expelled through mouth

Front 10

How do annelids digest food?

Back 10

Earthworms have one-way digestive tract with mouth and anus, allowing for specialization

Specialized parts: mouth, pharynx, esophagus, crop (store food), gizzard (grind food), intestine (absorb nutrients), anus

Front 11

How do arthropods digest food?

Back 11

Insects have similar digestion system to earthworms

In addition, have jaws for chewing and salivary glands

Front 12

What is the digestive tract in humans?

Back 12

Oral cavity -> pharynx -> esophagus -> stomach -> small intestine -> large intestine -> anus

Front 13

What are the accessory organs for human digestion?

Back 13

salivary glands, pancreas, liver, gall bladder

Front 14

What enzyme does saliva have and what does it do?

Back 14

Saliva contains enzyme "Salivary Amylase" which hydrolyzes starch to maltose

Front 15

What is peristalsis?

Back 15

Rythmic involuntary contractions that move food down esophagus

Front 16

What does the stomach do?

Back 16

Stores and partially digests food

Walls lined with thick mucosa and contains the glands that secrete mucus that protects stomach from acid

Secretes pepsin and HCl

Front 17

What does pepsin do?

Back 17

Protein-hydrolyzing enzyme

Front 18

What does HCl do?

Back 18

kills bacteria, dissolves intercellular "glue" holding food tissues together, activates certain proteins

Front 19

What is chyme?

Back 19

Acidic, semi-fluid, mixture of partially digested food

Front 20

Where does food go after stomach?

Back 20

Passes through pyloric sphincter to the duodenum of the small intestine

Front 21

Where does chemical digestion finish?

Back 21

Small intestine

Front 22

What are the parts of the small intestine?

Back 22

Duodenum
Jejunum
Ileum

Front 23

What is the purpose of the small intestine?

Back 23

Highly adapted for absorption

Front 24

Why is small intestine so long?

Back 24

Increase surface area for absorption

Front 25

What is the purpose of villi in small intestine?

Back 25

Small finger-like projections in small intestine

Villi contain blood vessels and lymphatic vessels that help absorption of blood

Front 26

Where does most of the digestion occur in the small intestine?

Back 26

Duodenum where secretions of intestinal glands, pancreas, liver and gall bladder mix with acidic chyme

Front 27

What does the intestinal mucosa secrete?

Back 27

Lipases (fat digestion)
Aminopeptidases (polypeptide digestion)
Disaccharidases - digestion of maltose, sucrose, lactose)

Front 28

What does the liver do?

Back 28

Produce bile which is stored in gall bladder prior to release in small intestine

Front 29

What does bile do?

Back 29

contains no enzymes, emulsifies fat, breaking large globules into smaller droplets

Front 30

What does the pancreas do?

Back 30

Produces enzymes such as amylase (carbohydrate digestion), trypsin (proteins), lipase (fats)

Secretes bicarbonate rich juice that neutralizes acid chyme arriving from the stomach

Pancreatic enzymes operate optimally at this higher pH

Front 31

What is the purpose of the large intestine?

Back 31

Absorption of salts and water

Front 32

What is purpose of rectum?

Back 32

Transient storage of feces

Front 33

Do plants have a digestive system?

Back 33

No, but they do have similar digestive processes coordinating utilization of nutrients with their production

Front 34

Describe intracellular digestion in plants

Back 34

Store insoluble polymers, starches, lipid and proteins in cells

Principle storage food is starch

When nutrients needed, starch broken down by hydrolysis and used by cell or transported by diffusion to other cells

Front 35

Why does the venus fly trap eat flys?

Back 35

To obtain nitrogen in nitrogen poor soils, NOT for food, they are still autotrophs

Front 36

Describe extracellular digestion in plants:

Back 36

Enzymes are excreted, more simpler substances are absorbed