Question

The plasma membrane serves many functions, many of which depend on the presence of specialized membrane proteins. Which of the following roles of the plasma membrane could still occur if the bilayer were lacking these proteins?

1) Transport of molecules across the membrane
2) Cell recognition and signaling
3) Cell adhesion
4) Regulation of cell shape and movement

Answer 1

Without specialized membrane proteins, the plasma membrane can still enable simple diffusion and osmosis but would be impaired in functions like cell recognition, signaling, adhesion, and regulation of cell shape and movement.

Step-by-step explanation:

The plasma membrane is a crucial component of a cell, primarily responsible for protecting and maintaining the cell's integrity. Without specialized membrane proteins, some functions of the plasma membrane would be greatly reduced but not completely inhibited. For instance, simple diffusion and osmosis, which are passive transport mechanisms, could still occur given their nature as processes that do not necessarily require proteins.

However, the plasma membrane without proteins would not be efficient in cell recognition, signaling, cell adhesion, or the regulation of cell shape and movement, which are all heavily reliant on the presence of integral and peripheral proteins.