Question

you have isolated a yeast strain with a genetic mutation that increases the hydrophobic nature of the transmembrane domains of one of its ion channels. what is the most probable outcome? less energy will be required to move the ion across the membrane. ion channel specificity will change to allow different ions across the membrane. more energy will be required to move the ion across the membrane. the diffusion rate of the ion across the membrane will decrease. the diffusion rate of the ion across the membrane will increase.

Explanation:

Ion channels are integral membrane proteins that facilitate the movement of ions across the membrane. The transmembrane domains interact with the lipid bilayer. A more hydrophobic transmembrane domain would likely interact more strongly with the non - polar lipid bilayer. This stronger interaction could impede the movement of ions through the channel. Diffusion rate is related to how easily the ion can pass through the channel. A more hydrophobic (and thus more "stuck" in the membrane) channel may not allow ions to pass as freely.

Answer:

The diffusion rate of the ion across the membrane will decrease.