Q. 14

[kbshah6109]

How are you supposed to attack a question like this if you did not know that cyanide prevents electrons from passing through a cytochrome in ETC. That information wasn't given in the passage or in the question stem.
I thought that since cyanide is negatively charged, there would be an increase in negative charge inside the cell, and thus sodium would enter the cell to counter this.

Any thoughts on how to attack a question like this would be appreciated.

[admin]

There are usually only a few questions in Biological Sciences that directly tests knowledge (like this one) and even if you missed a few of them, you can still ace this section of the exam since it is mostly based on reasoning/tables/graphs/experiments, etc.

Your reasoning does not work here because the plasma membrance is semi permeable and it is not leaky to sodium (as opposed to potassium); similarly, CN-, compared to K, is large and in conjuction with its charge means that it won't cross the membrane. Instead it can affect something that is associated with the membrane: the channel.

[admin]

bump

[hua8986059]

Its just one of those facts you've gotta know I guess， I remember reading it somewhere.