Final Notes

Question 1

2 big challenges

Answer 1

need O2

get rid of metabolic wastes

Question 2

are marine inverts conformers or regulators

Answer 2

conformers

less energy expenditure

mirror osmolarity of seawater using osmolytes

Question 3

sharks use what osmolytes

Answer 3

TMAO and urea to inc. osmolarity of cells

need less NaCl

Question 4

how does rectal gland work

Answer 4

Na/K ATPase basal surface + Na/2Cl/K cotransport

Cl channel in apical –> Cl- out for electrochem gradient

K channel basal –> K+ out

Na into lumen driven by electochem gradient of Cl- out

Question 5

metabolic wastes balance btw water loss and energy costs

Answer 5

most toxic + water needed ammonia –> urea –> uric acid

most energy uric acid –> urea –> ammonia

Question 6

pH of urine and why isnt it lower

Answer 6

6 b/c H+ secreted into it + small amount of bicarb

buffers keep pH from being too low

Question 7

mealworm tenebrio system

Answer 7

countercurrent system makes hypertonic urine

active KCl out of rectum and water follows

Question 8

evaporative water loss things in insects

Answer 8

cuticle waxy layer keeps water in, but heat melts it

trachea open and close spiracles

breathing air in warmed and humidified, out is cooled and water condenses