Photo AI
Vibrio cholerae produces a toxin that binds to a plasma membrane receptor on intestinal cells of the host - VCE - SSCE Biology - Question 12 - 2011 - Paper 1
Question 12
Vibrio cholerae produces a toxin that binds to a plasma membrane receptor on intestinal cells of the host. The toxin permanently activates the G protein in target ce... show full transcript
Worked Solution & Example Answer:Vibrio cholerae produces a toxin that binds to a plasma membrane receptor on intestinal cells of the host - VCE - SSCE Biology - Question 12 - 2011 - Paper 1
Step 1
A. disrupts normal signal transduction in the cell.
Answer
The V. cholerae toxin primarily disrupts normal signal transduction within the cell. By permanently activating the G protein, it interferes with the usual signaling pathways, leading to the rapid loss of water from the cells, which results in severe dehydration. This mechanism classifies it as a pathogenic factor that impacts cellular communication.
Step 2
B. is an example of a second messenger molecule.
Answer
This statement is inaccurate. The V. cholerae toxin itself is not a second messenger. Instead, it acts on the G protein, which is part of the signaling cascade that could include second messenger molecules, but does not fit the definition of one.
Step 3
Step 4
D. acts as a neurohormone.
Answer
This statement is also incorrect. While the cholera toxin has systemic effects, it does not function as a neurohormone. Neurohormones are typically released by neurons and have targeted actions, whereas the cholera toxin primarily induces its effects through direct action on intestinal cells.