lec 10

Question 1

how can collared lizards exhibit a relationship between metabolism and survival?

Answer 1

those with higher burst speeds end up with more offspring.

could be due to many things - for instance, a collared lizard with higher burst speed may be able to escape predators, and so has more children

Question 2

what animals exhibit a relationship between metabolism and survival?

Answer 2

collared lizards, with higher burst speeds and more offspring reared

Question 3

“glucose can be fully oxidized, or not. why?”

Answer 3

while aerobic activity oxidizes glucose, anaerobic activity is also working in the background - just to a lesser extent

Question 4

how does uptake rate of O2 compare to usage rates? (ie does it match idealized chart?)

Answer 4

uptake rate lags behind a bit as system ‘turns on’ - we incur a little bit of debt called the Excess Post-exercise Oxygen Consumption (EPOC) debt.

Question 5

what is the difference between SO and FG muscle fibres? how might a soccer player exhibit both?

Answer 5

SO = slow oxidative, which is good for going at something for a long time

FG = fast glycolytic, which is good for burst activity

soccer player uses SO for running for a long time, FG for stronger kicks

Question 6

compare light submaximal, heavy submaximal, and supramaximal exercise

Answer 6

both light and heavy submaximal stay under the max rate of O2 consumption - the difference lies in the amount of work put in, and the O2 debt incurred afterwards

supramaximal goes above the maximum rate of O2 consumption, turning into burst ANAEROBIC activity, with highest debt incurred after

Question 7

what do brine shrimp tell us about control over metabolic rates? explain the experiment

Answer 7

when brine shrimp experience anoxia, lactic acid is produced in anaerobic processes.

scientists attempted to trick the brine shrimp by deacidifying the blood by introducing ammonia, and it worked a bit, but the shrimp had real eyes that realized real lies and turned metabolism back off.

when oxygen was reintroduced to the environment, not only did aerobic metabolism resume, it resumed at a higher rate than before (EPOC)

Question 7

why are turtles less affected by anaerobic pathways?

Answer 7

calcium in shell acts as a buffer for protons - when acid builds up, it gets stored in the physical structure of the turtle shell

obviously the turtle isn’t impervious, but it helps it deal with lactic acid buildup a lot better

Question 7

why does oxygen consumption not increase proportionally to available oxygen concentrations in the air?

Answer 7

bodies only need a certain rate of oxygen –> anything higher would be a waste of effort and more importantly, energy

Question 7

redline darters are built for rivers where oxygen is more available, while slack-water darters are built for sitting bodies of water. if they are genetically close cousins, could the redline darter feasibly adapt to lower oxygen conditions?

Answer 7

the redline darter is more adapted to having higher O2 concentration to be able to budget energy elsewhere. theoretically, u could breed redline darters that survive lower oxygen conditions until u get near-anoxic conditions, at which point u would observe a variety of changes in energy partioning.

Question 8

what animals can control their metabolic rates? what do they do?

Answer 8

brine shrimp experiment

1. turned off oxygen and observed shrimp underwent anaerobic metabolism
2. knowing lactic acid is a byproduct of anaerobic metabolism, scientists introduced ammonia to neutralize the blood pH to trick the shrimp
3. the shrimp, smelling a rat, turned on metabolism a bit but realized O2 was still unavailable and went back to anaerobic
4. scientists reintroduced O2 to the environment, and the shrimp consumed oxygen at a higher rate than before (EPOC)

Question 8

hey! what the fuck is goldfish doing in anoxic conditions

Answer 8

anaerobic pathway doesn’t result in buildup of lactic acid, the byproduct is ethanol LMAO