Need to excrete waste Flashcards
How are proteins digested
- oxidative deamination
- protein becomes ammonia and carbon molecule (krebs)
Tube within a tube
- the inside of a tube within the body is an OUTSIDE the body surface (digestive system, excretory system up until bowmans capsule in nephron)
Where does intracellular waste come from?
- cellular reactions in metabolism and cell respiration
- drug and toxin metabolism
What are examples of intracellular wastes?
- Co2, H2O, NH4+, PO4+
How is waste excreted out of single cells?
diffusion
How is waste excreted out of more than just one cell? Why is the process diff than with 1 cell?
- waste from other cells diffuse into ECM causing hypertonic env. diffusion no longer works
- combo of circulatory and excretory system
What is the main purpose of the excretory system
- remove non-solid wastes from body
Where does the excretory system rid of its waste? What wastes go through where?
- lungs: Co2 and H2O
- sweat glands/skin: H2O and salts
- Kidneys: Nitrogen waste out through pee
Ammonia (solubility, toxicity and what animals)
- highly soluble
- highly toxic
- aquatic organisms
Urea (solubility, toxicity and what animals)
- less soluble
- less toxic
- terrestrial organisms
Uric acid (solubility, toxicity and what animals)
- not soluble
- less toxic
- egg laying organisms
Why urea?
- land animals need to conserve H2O
- Also need to detoxicize ammonia waste since pee is concentrated. If it was ammonia and not urea, we’d be in trouble
- (urea big = less soluble = less toxic)
What is urine composed of?
- urea
- salts
- excess sugar
- H2O
- urobilin
Where/How is urea made?
- 2NH3 + CO2 = urea
- made in liver
Why uric acid?
- egg laying animals have no place to excrete waste inside of egg
- need a very insoluble material so it stays away from embryo
- (uric acid = even bigger = less soluble = less toxic)
What is uric acid in baby and adult?
POLYMERIZED UREA
- precipitates out of soln (white dust in egg)
- white paste in adults (lighter so easier to fly for birds)
Osmoregulation
The homeostasis of water concentration
(measured by concentration of solute)
osmoregulation in freshwater organisms
- hypotonic (salty inside)
- salt loss due to conc grad (reabsord salt)
osmoregulation in saltwater organisms
- isotonic: same saltiness in fish and in water. no net mvmt of H2O
- hypertonic: water more salty so lose H2O. gulp water to fix
osmoregulation in land organisms
- need to conserve H2O and salt
