Question

Cell membranes are asymmetrical. Which of the following is the most likely explanation?

A) The cell membrane forms a border between one cell and another in tightly packed tissues such as epithelium.
B) Cell membranes communicate signals from one organism to another.
C) The two sides of a cell membrane face different environments and carry out different functions.
D) The "innerness" and "outerness" of membrane surfaces are predetermined by genes.
E) Proteins can only be associated with the cell membranes on the cytoplasmic side.

Answer 1

The most likely explanation for cell membrane asymmetry is that the two sides of a cell membrane face different environments and fulfill different functions, crucial for processes like tissue development and immune response.

Step-by-step explanation:

The cell membranes are asymmetrical primarily because the two sides of a cell membrane face different environments and carry out different functions. This asymmetry is essential for the diverse roles the membrane plays in cellular function, such as communication and selective transport. The inner and outer layers of the plasma membrane are composed of different sets of proteins and lipids that are adapted to the cell's internal environment and the extracellular space, respectively. For example, on the interior of the membrane, some proteins anchor the membrane to the cytoskeleton, while on the exterior, different proteins and carbohydrates play roles in cell-cell recognition and signaling. This functional differentiation is crucial for processes like tissue and organ formation and the immune system's ability to distinguish self from non-self.