Question

In the fluid-mosaic model of the plasma membrane, the phospholipid molecules are oriented so that the ________ heads are facing the outside environment and the ________ tails are facing the interior of the membran.
a) autotrophic, heterotrophic
b) ectothermic, endothermic
c) hydrophilic, hydrophobic
d) hydrophobic, hydrophilic

Answer 1

Answer:

The correct answer is option c) "hydrophilic, hydrophobic".

Explanation:

Phospholipids are amphipathic molecules, which means that they have an hydrophilic and an hydrophobic component. This characteristics make phospholipids essential molecules for cell's membranes. In cell's membranes, phospholipid molecules are oriented so that the hydrophilic heads are facing the outside environment and the hydrophobic tails are facing the interior of the membrane. This allows the cells to be suspended in aqueous solutions, while the inner of the cell is protected by a layer of hydrophobic tails.