Question 18M.3.HL.TZ1.22
| Date | May 2018 | Marks available | [Maximum mark: 6] | Reference code | 18M.3.HL.TZ1.22 |
| Level | HL | Paper | 3 | Time zone | TZ1 |
| Command term | Explain | Question number | 22 | Adapted from | N/A |
Explain how an increase in cell respiration in a tissue causes increased release of oxygen by hemoglobin in the tissue.
[6]
a. cell respiration consumes O2 / lowers O2 partial pressure in tissues
b. (actively) respiring tissues release CO2 / partial pressure of CO2 increases
c. CO2 increases acidity / lowers pH of the blood
d. decreases hemoglobin’s affinity for O2
e. promotes the release of oxygen to respiring cells/tissues
f. binding of hydrogen ions/ allosteric effect / conformational change in hemoglobin releases O2 more readily
g. more oxygen released at the same partial pressure
h. this shifts the oxygen dissociation curve to the right/Bohr shift
These points can be presented in a graph.
diagram with correct labels:
i. partial pressure O2 on x-axis and (percentage) saturation hemoglobin with O2 on y-axis
j. exponential shape curve at lower partial pressure/concentration of O2
k. curve shifted to right (and lower) for higher partial pressure /concentration of CO2 /lower pH
