Ch. 21 Nutrition & Digestion Flashcards
What are the 2 major modes of nutrition?
1) Autotrophs “self feeding”
2) Heterotroph “feed on other organisms”
What are the 2 types of autotrophs?
1) Chemoautotrophs - chemosynthesis
2) Photoautotrophs - photosynthesis
What are the 2 types of heterotrophs?
1) Absorptive - digest food outside (via body surface)
2) Ingestive - to eat; internal digestion
- herbivores, carnivores, omnivore
What are the 4 stages of food processing?
1) Ingestion
2) Digestion
3) Absorption
4) Elimination
Ingestion
Act of eating; putting food in body
1) Suspension feeders “filter feeds”
2) Substrate feeders
3) Fluid feeders
4) Bulk feeders
Suspension feeders
“Filter feeders”
- obtain food molecules suspended in water
- ex. whales, clams, oysters, scallops
Substrate feeders
Live/on food source; eat way thru it
- ex. caterpillars, snails, earthworm
Fluid feeders
Suck nutrient rich fluids from plant/animal
- ex. mosquitos, hummingbirds, ticks
Bulk feeders
Ingest large pieces of foods; specialized body parts to ingest large pieces (jaws, pincers, fangs)
- ex. wolf, octopus, people, buffalo, frog
Digestion
Breaking large complex food molecules into smaller, simpler monomers
- 2 phases: Mechanical breakdown (chewing, muscle) & chemical breakdown (enzyme hydrolysis)
Function: Mechanical/chemical breakdown of food
Absorption
When small nutrient molecules are taken in by cells lining the digestive tract and transported via vessels
- used to make ATP and building material
Function: Transfer of nutrients into bloodstream (first to liver)
Elimination
No longer useful so elimination
- indigestible materials passes out of digestive tract
How do single celled organisms digest?
Intracellular digestion
- lysosomes combine with food vacuoles
How do simple multicellular organisms digest?
Gastrovascular cavity (one opening, most of body) - support, facilitate distribution of materials
How do complex multicellular organisms digest?
Complete digestive tract
- alimentary canal
- 2 openings w/ long tube
What does the type of specialized region of digestion depend on?
Type of habitat, types of food digested, and complexity.
Omnivores
An animal that eats both plants/animals
Herbivores
An animal that eats only plants
Carnivores
An animal that eats other animals
Why can’t animals use large polymers in organic matter directly?
1) macromolecules are too large to pass thru plasma membrane and enter cell
2) needs monomers to make polymers of own body
Gastrovascular cavity
A digestive compartment w/ a single opening, the mouth, may function in circulation, body support, waste disposal, and gas exchange, as well as digestion
- simple animals
Alimentary canal
Continuous passage way that extends 30ft from mouth to anus
- 8 specialized regions w/ unique structure/function
- A digestive tract consisting of a tube running b/w a mouth and anus
Accessory Organs
Not apart of the alimentary canal but attached to it and aids
- 4 regions: liver, pancreas, gallbladder, salivary glands
What are the 8 specialized regions of the alimentary canal?
1) Oral Cavity (mouth)
2) Pharynx (throat)
3) Esophagus (gullet)
4) Stomach
5)
6)
7)
8)
Oral Cavity
Structure that receives food (ingestion) and tastes food
- prepares food for swallowing
- carbohydrates digested here
- structures: teeth (32), tongue, salivary glands
What is the function of teeth?
Break down food into smaller pieces
- increases surface area for enzymes
What is the function of the tongue?
Most muscular organ, speech but also aids in chewing/swallowing
- taste buds
What is the function of salivary glands?
Produce saliva
- helps lubricate food for chew/swallow
- contains salivary amylase (begins carbohydrate digestion)
- antimicrobial agents (fight infection)
Pharynx
Digestive & respirator tract (food/liquid and air)
- receives bolus from mouth and passes to next region
- structures: tonsils, uvula, epiglottis
Tonsils
2 lymph glands that attacks foreign substances
Uvula
Deflect food downwards, not upward to nose