8.2. Transport of oxygen and carbon dioxide
A subsection of Biology, 9700, through 8. Transport in mammals
Listing 10 of 241 questions
Oxygen enters the blood stream from the alveoli in the lungs and carbon dioxide leaves the bloodstream to enter the alveoli. Most of the oxygen is carried by haemoglobin in red blood cells to the body tissues. Outline how oxygen enters the blood stream from an alveolus. is an oxygen dissociation curve for adult haemoglobin. The curve shows the affinity of haemoglobin for oxygen at the range of partial pressures found in the body. The values for plotting the curve are obtained in the laboratory by bubbling oxygen at different partial pressures through a solution of haemoglobin at 37 °C and pH 7.4. At a different temperature or pH the measured values will change, resulting in a different oxygen dissociation curve. partial pressure of oxygen / kPa percentage saturation of haemoglobin shows that the percentage saturation of haemoglobin changes at different partial pressures of oxygen. Use to calculate the difference in percentage saturation of haemoglobin at the lower partial pressure of oxygen of 2.7 kPa compared to the higher partial pressure of 13.0 kPa. Show your working. difference = Explain the advantage of having a difference in percentage saturation of haemoglobin at lower and higher partial pressures of oxygen. In a person with sickle cell anaemia, the ability of haemoglobin to transport oxygen and carbon dioxide is severely affected. The cause of this disease is a mutation in the gene coding for the β-globin polypeptide of haemoglobin. Define the term disease. Outline the differences between the HbA and HbS (sickle cell) alleles of the gene coding for the β-globin polypeptide and explain how these differences lead to a change in the haemoglobin molecule formed.
9700_s18_qp_23
THEORY
2018
Paper 2, Variant 3
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Questions Discovered
241