extra questions b9 Flashcards
Exercise cannot be sustained when anaerobic respiration takes place in muscle cells.
Explain why
muscles become fatigued / stop contracting because not enough energy is transferred
After 10 minutes the limewater in flask B was cloudy, but the limewater in flask A remained
colourless.
atmospheric air contains less carbon dioxide than exhaled air. Flask B goes more cloudy because carbon dioxide is produced in aerobic respiration by
woodlice
The earthworms took in less oxygen each minute at 10°C than they took in at 20°C.
Explain why.
lower rate of respiration
worms release less energy
During exercise, more oxygen is carried to the working muscles.
Explain why this is helpful during exercise
for respiration
- energy released
- prevents anaerobic respiration
- prevents build-up of lactic acid
Explain why the man’s breathing rate increased when he was running.
- get more oxygen
- for respiration
- remove more carbon dioxide that is produced in respiration
Give two other changes in the body that help to increase the amount of oxygen delivered to the working muscles during exercise.
blood diverted from elsewhere
increased breathing rate
Why is more lactic acid made in the muscles when running at 14 km per hour than when running at 8 km per hour?
more energy is needed
not enough oxygen can be supplied to muscles
so more anaerobic respiration
Respiration is a process which takes place in living cells. What is the purpose of respiration?
to release energy
Suggest an explanation for this relationship: the higher the rate of oxygen consumption, the shorter the
time taken to complete
the faster oxygen is taken into the blood,
the faster energy can be released in the muscles,
and the faster the athlete can run
Explain the advantage to the students of the change in heart rate during exercise.
Respiration is higher
increases rate of delivery of oxygen and increases rate of delivery of glucose
and results in faster removal of carbon dioxide and lactic acid
The student repeated the run with the treadmill set at 16 km per hour.
The student’s heart rate took 3 minutes longer to return to the normal resting rate than when running at 12 km per hour.
Give reasons why it took longer to recover after running faster.
higher heart rate
* more energy needed
* more O2 needed
* (more) anaerobic respiration
* (more) lactic acid to be broken down by oxygen debt
Explain how the change in blood flow to the athlete’s muscles helps him to run.
supplies (more) oxygen
supplies (more) glucose
for (more) respiration
releases (more) energy (for muscle contraction)
Give one effect smoking can have on the body
Lung cancer
Give two uses for energy released in respiration
- Active transport
- Movement
Describe two differences between aerobic and anaerobic respiration in humans
- Anaerobic respiration produces lactic acid and aerobic does not
- Anaerobic respiration produces less energy than aerobic respiration
Suggest why the concentration of carbon dioxide in the tube stayed the same between day 0 and day 5
- the pond snail and pondweed were respiring, releasing carbon dioxide
- the pond weed was taking in carbon dioxide for photosynthesis
- rate of respiration = rate of photosynthesis
Suggest why the concentration of carbon dioxide increased between day 5
and day 1
- plant can no longer photosynthesise so is no longer taking in carbon dioxide
- snail and pond weed are respiring, releasing co2
Explain the ways the man’s body responded to exercise
- heart rate increased
- to increase blood flowing to muscles
- to provide more oxygen and glucose to muscles
- to remove carbon dioxide and lactic acid more quickly from muscles
- breathing rate increased
- supplies more oxygen to lungs
- so more oxygen to blood
- more carbon dioxide removed
- more oxygen to muscles
- needed for increased respiration
- to release energy
- for muscle contraction
Describe two differences in the response of person R and person S to the exercise.
- heart rate increased more slowly for R than S
- R’s heart rate rose less than S
A student made the following hypothesis about the heart rate of smokers
and non-smokers during exercise.
“During exercise, the heart rate of smokers increases more than
the heart rate of non-smokers.”
Design an investigation that would allow you to test this hypothesis
- there will be two groups of five people: non-smokers and smokers
- each person will run on the treadmill at 10km/h for 10 mins
- the control variables will be: same number of people in each group, same gender, same level of activity, same age, no health issues
- record heart rate for each person before and after exercise
- calculate increase in heart rate for each person after exercise
- compare results for each group
Flask A acts as a control in this investigation.
What is the purpose of a control?
To act as a comparison
The student repeated the investigation with no woodlice.
Describe the appearance of the limewater in flask A and flask B after 10 minutes
Flask A: colourless
Flask B: colourless
Respiration transfers energy from glucose for muscle contraction.
Describe how glucose from the small intestine is moved to a muscle cell.
- glucose is absorbed by diffusion into the bloodstream
- then the blood delivers glucose to muscles and capillaries
Suggest how the experiment could be changed to give a reproducible way
to measure the rate of the reaction.
Include any apparatus you would use.
Collect volume of co2 produced in a gas syringe for one minute using a timer
