(1) Digestion

Question 1

Feeding Mechanisms

Answer 1

1. Suspension feeding/ filter feeding (porifera)
2. Deposit Feeding (annelida)
3. Selective Feeding

Question 2

Digestive Systems

Answer 2

1. Incomplete
2. Complete

Question 3

Incomplete Digestive System

Answer 3

only one opening =mouth/anus

Example: planaria, cnidaria

Question 4

Complete Digestive System

Answer 4

Separate anus and mouth, one way flow

Example: mollusks, annelids

Question 5

Intracellular Digestion

Answer 5

Protista, Porifera

Question 6

Extracellular Digestion

Answer 6

Arthropoda, Chordata

Question 7

Intracellular & Extracellular Digestion

Answer 7

Cnidaria, planaria, roundworm

Question 8

Hydrolases

Answer 8

Hydrolytic enzymes that break organic molecules by addition of water

Question 9

Food movement through alimentary canal

Answer 9

1. Cilia: Platyhelminthes, Nematoda, most mollusks
2. Segmentation: mixing in intestine and stomach
3. Peristalsis (around/spreading): movement through intestine

Question 10

Metazoan Alimentary Canal

Answer 10

1. Reception
2. Conduction
3. Storage and early digestion
4. Grinding
5. Terminal digestion and absorption
6. Water absorption, concentration of solids

Question 11

Receiving (alimentary canal)

Answer 11

a) ingestion, chewing, swallowing
b) salivary gland secretions
- lubricate
- initial hydrolysis
c) avoid choking
-epiglottis

Question 12

Conduction and storage (alimentary canal)

Answer 12

a) transport to the stomach
b) crop- storage in many invertebrates and birds

Question 13

Grinding & Early digestion (alimentary canal)

Answer 13

a) gizzard (grinding)
-muscular stomach subdivision
- birds and annelids, insects
- stones and grit swallowed, or hard lining
b)stomach (initial protein digestion)
- Cellulase not produced by metazoans, endosymbionts provide for some
- Gastric Juices: pepsin and HCL

Question 14

Pepsin

Answer 14

splits protein

Question 15

HCL Gastric Juice

Answer 15

kills bacteria, activates pepsin

Question 16

Terminal Digestion & absorption

Answer 16

the small intestine does MOST digestion/breakdown and absorption
- pancreatic juice
- bile
- membrane enzymes
- absorption

Question 17

Bicarbonate (Pancreatic Juice)

Answer 17

neutralizes acidic chyme = liquified food

Question 18

Trypsin/chymotrypsin (Pancreatic Juice)

Answer 18

proteases = protein digestion

Question 19

Lipase (Pancreatic Juice)

Answer 19

lipids fatty acids and glycerol

Question 20

Amylase (Pancreatic Juice)

Answer 20

carbohydrates

Question 21

Nucleases (Pancreatic Juice)

Answer 21

RNA and DNA, nucleotides

Question 22

Aminopeptidase (Membrane Enzymes)

Answer 22

terminal amino acids. breaking protein to amino acids

Question 23

Sucrase (Membrane Enzymes)

Answer 23

sucrose -> glucose + fructose

Question 24

Lactase (Membrane Enzymes)

Answer 24

lactose -> glucose + galactose

Question 25

Alkaline Phosphate (Membrane Enzymes)

Answer 25

phosphates compounds

Question 26

Absorption

Answer 26

1. Passive transport
2. Active Transport

Question 27

Water absorption & solids concentration (alimentary canal)

Answer 27

large intestine

Question 28

Regulation of Food intake

Answer 28

1. Hypothalamus (hunger center), monitors blood glucose
2. Stretching of stomach and duodenum
3. Brown fat (placental mammals): nonshivering thermogenesis

Question 29

Nutritional Requirements

Answer 29

1. Carbohydrates: energy and building block
2. Protein: mostly for building blocks. Amino Acids = essential, we have to ingest it
3. Lipids: energy and building block
4. Minerals: anion and cations; building blocks, physiology
5. Vitamins: simple organic molecules essential in diet
6. Water: solvent