Question

molecules readily pass through the membrane. another biologist alternatively hypothesizes that these types of molecules require channel and transport proteins that are embedded in the membrane in order to move across the membrane. which of the following data would best refute this alternative hypothesis? a ethanol is found in the cytosol of cells when they are briefly exposed to a ten percent ethanol solution. b cells become oxygen - deficient when membrane protein activity is blocked. c co₂ and n₂ movement in and out of cells is unaffected when membrane protein activity is blocked. d sodium ions cannot move across the cell membrane when membrane protein activity is blocked.

Explanation:

The alternative hypothesis is that certain molecules require channel and transport proteins to cross the membrane. Data that shows molecules moving across the membrane without the need for these proteins would refute it. Option C shows that $CO_2$ and $N_2$ movement is unaffected when membrane - protein activity is blocked, indicating they can cross the membrane without protein help.

Answer:

C. $CO_2$ and $N_2$ movement in and out of cells is unaffected when membrane protein activity is blocked.