TOPIC 4: Animal Digestion and Waste Management

requirement for cellular respiration

a supply of each reactants (sugar and protein)

a waste removal system (ammonia, CO2, and water)

mechanism that connects these (circulatory system)

basic nutritional requirements

carbon compounds and essential nutrients

essential nutrients

nutrients that we cannot make ourselves so we must ingest them:

• Some amino acids (8), some fatty acids (omega fatty acids), vitamins, and minerals (inorganic compounds like calcium and phosphates)

food processing steps

1) ingesting

2) digestion

3) Absorption

4) elimination

animal feeding mechanisms

• suspension feeding

• substrate feeding

• fluid feeding

• bulk feeding

suspension feeding

aquatic animals that feed on food filtered from the water

substrate feeding

when an organism feeds on its own environment; a worm inside a leaf, eating the leaf

fluid feeding

animals with a completely fluid diet; female mosquitoes feeding on blood

• they have special anticoagulants in their blood to prevent the blood congealing in their digestive tract

bulk feeding

animals that ingest food whole, or in pieces

intracellular digestion

digestion within a cell

• lysosomal enzymes

• cytoplasmic enzymes

lysosomal enzymes

present in the choanocytes and amoebocytes of sponges; helps with intracellular digestion

cytoplasmic enzyme

digest tri peptides into amino acids in intracellular digestion:

• in the epithelial cells of all Eumetazoa

extracellular digestion

digestion within a chamber; allows digestion of bigger particles

• almost all Eumetazoa

allows for specialization of digestive organs

the reason why an alimentary canal is more advantageous than a gastrovascular cavity

gastrovascular cavity

only one opening into the stomach

alimentary canal

digestive system with a mouth on one end of the tube, and an anus on the other end; one-way passage

cecum

organ that houses the cellulase used to break down cellulose; larger in herbivores because they have to process a lot of cellulose

nitrogenous waste

waste produced during the breakdown of proteins and nucleic acids

ammonia

nitrogenous waste created by aquatic animals; incredibly toxic

urea

nitrogenous waste produced by mammals, most amphibians, sharks and some bony fish

uric acid

nitrogenous waste release by birds, reptiles, insects, and land snails; insoluble in water which means it is completely non-toxic

urine production

1) filtration- of blood

2) reabsorption- of useful solutes like glucose

3) secretion- the body actively eliminating solutes

4) excretion- urine is released from the body