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What is nutrition?
- a. the taking in, taking apart and taking up of food
- i. Food consumed for both energy and the organic molecules used to assemble new molecules, cells, and tissues
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What does synthesis and degradation involve?
oxygen and nutrients
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Every organism needs to be __
a. able to synthesize and degrade organic materials; build up and break down organic molecules so that it could use those building blocks to build new molecules
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Two Classifications of organisms
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Autotrophs
- i. produce their own food
- 1. Usually photosynthetic organisms that use photosynthesis to produce organic molecules from inorganic molecules
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Heterotrophs
- 1. Incapable of making their own food
- a. Have to eat organic material made by autotrophs or organic material of other heterotrophs and they have to break it down into its building blocks and uses those building blocks to build up the organic molecules they need= DIGESTION
- b. Have to eat already synthesized organic material
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I. Heterotrophs
a. Classified according to the type of food they eat
What are they?
- i. Carnivores: mainly meat eating (almost exclusively if not exclusively)
- ii. Herbivores: plant eater
- iii. Omnivores: both meat and plants
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a. Based on classifications, there are __in the digestive system and organs of procurement in dealing with the food in animals that are herbivores, omnivores, and carnivores
Three examples.
modifications
- i. Dentition is an example
- 1. Carnivores: sharp teeth for ripping
- 2. Herbivores: since cellulose is difficult to break down, they have flat teeth for grinding
- 3. Omnivores: both
- 1. Giraffes and their long necks to reach on top of trees
- 2. Beaks and bills
- a. Shape determined by what birds eat
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Internal Modifications
1. Plant food is hard to digest; so, some animals deal with it by making their stomach (or other part of digestive system) into compartments just containing bacteria to break down cellulose
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What do cows do?
- a. Chews grass, puts it in one compartment, regurgitates and chews again (cows do this)
- i. Compartmentalization happens in some animals based on food
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1. __ of digestive tract varies among herbivores and omnivores
Length
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Types of Digestion in Heterotrophs who need to digest
intracellular and extracellular
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Intracellular Digestion
- i. Digestion within a cell so that the food by either pinocytosis or Phagocytosis takes it in, forms a food vacuole, fuses with lysosomes, gets digested, and the waste is exocytosed out
- ii. Getting material in and removing waste and being able to send it to rest of body
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Extracellular Digestion
i. Outside of cell
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How many types of extracellular and what are they?
- two
- one outside body in environment
- one within cavity
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Explain extracellular digestion in environment
a. Some animals release digestive enzymes from prey in environment
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Explain extracellular digestion withiin
a. Still extracellular because outside of cell, but inside digestive cavity= most advanced, especially inside digestive tract
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Intracellular DIgestion Organisms
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a. PROTISTA
- i. Unicellular organisms that undergo intracellular digestion
- 1. Phagocytosis or pinocytosis, Endocytosis, exocytosis
- ii. Keeps what it builds to make cellular parts and releases waste products
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PORIFERA: General Description
Multicellular organisms with very little differentiation in terms of organ systems; really don’t have organ systems; think of groups of cells living together
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Porifera have an __ that leads outside a body cavity called the __, which does not extend to the entire end of the body. Extends only __.
- osculum
- spongocoel
- partway through the organism
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Example of porifera
sponges--> intracellular--> choanocytes
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I. Extracellular Digestion
a. All multicellular organisms above __have a __
i. Havingone allows for __--> more efficiency
ii. Also allows for organism to __, which wouldn’t be able to get into single cell
- porifera
- digestive cavity
- specialization of the cavity; special compartments; special regions
- digest larger pieces of food
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Cnidarians
Example
- a. multicellular organisms with a digestive cavity
- i. Use both extra and intracellular digestion
- hydra
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Cnidarians
1. Cnidocyte: __
2. Cavity is __ cavity
- cell that carries out digestion
- gastrovascular
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a. __(flatworms)
i. Planaria
1. __digestion
2. Different components:
a. __
- Platyhelminthes
- Extra and intracellular
- mouth, pharynx and gastrovascular cavity- highly branched
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