8.2. Transport of oxygen and carbon dioxide
A subsection of Biology, 9700, through 8. Transport in mammals
Listing 10 of 241 questions
In mammalian red blood cells, carbonic anhydrase has an important role in the transport of carbon dioxide. Carbonic anhydrase is an enzyme. Outline the features of an enzyme. Complete to show the reversible reaction involving carbonic anhydrase that takes place within red blood cells. body tissues lungs A ribbon structure of a molecule of carbonic anhydrase is shown in . The zinc ion is associated with the active site of the enzyme and is essential for the enzyme to function. zinc ion The molecule of carbonic anhydrase has primary, secondary and tertiary structure. Explain the extent to which shows the primary, secondary and tertiary structure of carbonic anhydrase.
9700_m19_qp_22
THEORY
2019
Paper 2, Variant 2
View
In a double circulatory system, blood passes through the heart twice in one complete circuit of the body. The complete circuit consists of the pulmonary circulation and the systemic circulation. is a diagram of a vertical section through the mammalian heart. The differences in the thickness of cardiac muscle in the walls of the four chambers of the heart are shown. right atrium left atrium left ventricle cardiac muscle right ventricle Explain, with reference to their functions, the difference in the thickness of the walls of the left ventricle and right ventricle of the heart. The alveolus is the gas exchange surface in mammals. For efficient oxygen uptake, a steep diffusion gradient is maintained between the alveolar air and the blood. Suggest how the steep diffusion gradient for oxygen is maintained at the gas exchange surface. Compared to when they were non-smokers, the ability of people who smoke tobacco to deliver oxygen to their body tissues is reduced. Two causes of this reduction include: • a decrease in the volume of air per breath moving towards the alveoli • a decrease in the ability of red blood cells to carry oxygen. Suggest one reason why smoking tobacco, even after only a short time, may cause a decrease in the volume of air per breath moving towards the alveoli. Explain why smoking tobacco causes a decrease in the ability of red blood cells to carry oxygen.
9700_m19_qp_22
THEORY
2019
Paper 2, Variant 2
View
Questions Discovered
241