For each disease named, state whether it is caused by a eukaryotic or prokaryotic organism. cholera; malaria; TB.
State the term used for an organism that causes diseases such as cholera, malaria and TB.
Malaria is caused by species in the genus Plasmodium. Ring cells are one stage in the complicated life cycle of Plasmodium and occur inside red blood cells. Fig. 2.1 is a scanning electron micrograph showing two ring cells, enclosed by the membrane of a red blood cell, which has just lysed (burst). The true diameter of the ring cell along the line X-Y is $2\,\mu\text{m}$. Calculate the magnification of the image shown in Fig. 2.1. Give your answer to 3 significant figures.
Describe how Plasmodium is transmitted from a person with malaria into the blood stream of an uninfected person.
After a red blood cell is infected, a much larger proportion of PS is found in the outer layer of the cell surface membrane, facing blood plasma. Suggest how the presence of PS in the outer layer can cause a response in a phagocytic cell.
Suggest why some uninfected red blood cells in a person with malaria can also be destroyed by phagocytic cells.
Research has shown that Plasmodium uses cholesterol from the cell surface membrane of the red blood cell it has infected. Suggest why cholesterol is needed by Plasmodium.
The use of cholesterol by Plasmodium causes a decrease in the quantity of cholesterol in the cell surface membrane of the red blood cell. Outline how a decrease in cholesterol could affect the cell surface membrane of the red blood cell.
Phospholipids can sometimes move between layers without the help of an enzyme, so the continued action of flippase and floppase is needed. With reference to Table 2.1, explain why the action of the enzymes flippase and floppase involves the hydrolysis of ATP.
Blood plasma has a higher concentration of $\text{Ca}^{2+}$ than the cytoplasm of red blood cells. Suggest one way in which a red blood cell can have a very low concentration of $\text{Ca}^{2+}$ when blood plasma has a higher concentration of $\text{Ca}^{2+}$.
The concentration of $\text{Ca}^{2+}$ within the red blood cell increases when the cell is infected with the malarial parasite. This leads to the loss of membrane asymmetry. With reference to Table 2.1, suggest and explain how membrane asymmetry is lost when the concentration of $\text{Ca}^{2+}$ within the red blood cell increases.