Cholera bacteria secrete the enzyme neuraminidase, and this enzyme changes proteins on the membranes of epithelial cells in the small intestine. These surface molecules then act as receptors for the toxin choleragen. The toxin promotes the secretion of chloride ions into the lumen of the small intestine.
(a(i))[1]
Name the pathogen responsible for cholera.
(a(ii))[1]
Suggest how chloride ions are moved out of the epithelial cells and into the lumen of the small intestine.
(a(iii))[3]
Explain how cholera bacteria are passed from one person to another.
(b)[4]
Using the information in Fig. 4.1, explain how the responses to the first injection and the booster injection differ.
(c)[4]
Discuss the difficulties involved in stopping the spread of cholera.
Worked solution & mark scheme
This 13-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Vibrio cholerae” …