Introduction to animal physiology and animal nutrition Flashcards
Lecture 23
Define a heterotroph
Animals that ingest food to satisfy their energy requirements
Define a autotrophs
Autotrophs are organisms that can produce their own food from the substances available in their surroundings using light (photosynthesis) or chemical energy
Identify the three basic classes of fuel used by all animals
Carbohydrates
Protein
Fats
Why must macromolecules be broken down before they can be used
macromolecules are too large to pass through membranes and enter cells
macromolecules used by the body are not the same as macromolecules in food, so
monomers must be reassembled into different forms in the body
Define intracellular digestion
Food particles are brought into body cells by phagocytosis and digestion occurs inside vacuoles
Define extracellular digestion
chemical digestion occurs outside the body cells
Define gastro-vascular cavity
The GI tract is a tube into which digestive enzymes are excreted - the contents of the tract are always ‘outside’ the body.
Define alimentary canal
Has two openings, one at either end, allowing food to move through in only one direction
What are the 3 benefits of having an alimentary canal
1) Allows organisation of the specialised compartments for storage
2) Enzyme can function optimally in each compartment leading to increase digestive efficiency
3) Animal is able to ingest additional food before previous food is digesting
What are the four stages of food processing? What happens in each stage?
Ingestion - obtaining food and introducing it into the GI system
Digestion - Physical and chemical breakdown of food
Absorption - passage of nutrients
Elimination - passage of undigested material out of the GI tract
Why do herbivores have longer intestines than carnivores?
Vegetation is very hard to digest
Explain how human dentition is adapted for an omnivorous diet
They often have long, sharp, pointed teeth to rip and cut meat and flat molars to crush plant material.
