Question

The main function of plasma membrane
A. Maintain cell shape and size
B. Control of all cellular activity
C. Regulate the flow of materials into and out of the cell
D. Store cell material

Answer 1

Hint: The plasma membrane is a lipid bilayer structure that helps to provide cell. The lipid bilayer is made up of a hydrophobic head and two hydrophilic tails. Proteins are embedded in the lipid layers and some carbohydrates are also seen in the membrane.

Step by step answer:The main functions of the plasma membrane are as follows:
-The plasma membrane form specialized compartments that help in selective permeability by providing
a unique environment to the cells (Create concentration gradients across the cell, pH, and electrical and ionic charge differences across the cell).
-Asymmetric protein distribution throughout the membrane
-Cell-Cell recognition by the presence of different carbohydrates, proteins, and lipids.
-Cell membrane is the site for a receptor that binds different molecules for cell signaling (receptor can bind with a ligand for example a hormone, it induces intracellular reactions).
-Controls and regulates reaction sequences (product of one enzyme is the substrate for the next enzyme, can arrange the enzymes in the proper sequence for their sequential activity).
Thus, the correct answer can be options A, B and C.

Note: When one hydrophilic tail of the lipid molecule is removed experimentally, the structure of the lipid bilayer changes to a spherical structure. This is known as micelles.