Respiration and gas exchange

Question 1

Explain the effect of physical activity on the pH of blood [3]

Answer 1

ph dec
increased rate of anaerobic resp
more co2
forms acid/co2 is acidic
anaerobic resp occurs
lactic acid produced

Question 2

Explain why lactic acid conc in blood in trained cyclists different from untrained cyclists after exercise [4]

Answer 2

lower anaerobic respiration
less lactic acid produced
bc more oxygen supplied to muscles
less oxygen debt
less oxygen required to breakdown lactic acid
quicker breakdown of lactic acid

Question 3

Suggest and explain why a sprinter can use anaerobic resp during race while marathon runner needs to use aerobic resp [4]

Answer 3

short time for sprinter
sprint needs lots of energy quickly
sprint oxygen supply not sufficient
anaerobic doesnt need oxygen
lactic acid removed after sprint
ref to oxygen debt

Question 4

Crickets respiring aerobically in closed jar. Explain why temp inc [2]

Answer 4

heat released by crickets
ref to ke
pressure inc
inc co2 greenhouse effect
small closed space