Explore how breathing and circulation continually renew oxygen and carbon-dioxide gradients needed for efficient gas exchange in IB Biology SL B3.1.3.
Compounds of carbon, hydrogen and oxygen are used to supply and store energy.
Describe how a concentration gradient of oxygen is maintained between the lungs and blood capillaries.
a. gas exchange takes place between the alveoli and capillaries;
b. alveoli surrounded by (dense) network of blood capillaries;
c. blood returning to alveolar capillaries is low in oxygen;
d. ventilation brings air rich in oxygen into the alveoli/lungs;
e. there is a higher concentration of oxygen in alveoli than in blood capillaries;
f. oxygen diffuses from alveoli/lungs to capillaries (moves down a concentration gradient);
e. Accept converse.
4 max