What are the differences between plasma membrane and cell membrane?

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Accepted Answer

Plasma membrane and cell membrane are two types of selectively semipermeable boundaries that are made up of a phospholipid bilayer. There are several differences between these two types of membranes.

Basis of differentiation
Plasma membrane
Cell membrane

Definition
Is a semi-permeable barrier that encapsulates individual organelles in a cell or an entire cell
Is a semipermeable membrane that surrounds the entire cell and its contents, including the cytoplasm and all the organelles

Structure and Composition
Structure and composition may vary depending on which organelle it surrounds and that organelle’s requirements
Composed of a phospholipid bilayer embedded with integral proteins that span the membrane, providing pathways for the movement of molecules through the membrane

Role in protecting again invaders
Does not play a protective role
Plays a role in protecting the cell from viral and bacterial invasions

Role in maintaining tonicity 
Does not play a role in maintaining tonicity
Plays a role in maintaining correct tonicity

Functions

Exact functions may vary depending on which organelle it is surrounding;
Providing a selectively permeable barrier between organelles and cytoplasm

Protecting the cell from outside invaders such as bacteria and viruses;
Regulating tonicity of cellular contents;
Providing a selectively permeable barrier;
Assists in signal transduction mechanisms at the cell surface

Feeding and movement
Are not modified in any way; cilia may not be present
May be modified in some organisms to facilitate movement and feeding; cilia may be present

Signal transdution
 Do not contain initial receptors for signal transduction mechanisms      
Contains the initial receptors for signal transduction mechanisms

Role in cytokinesis
Do not play a role in cytokinesis
Play a role in cytokinesis during cell division

Basis of differentiation	Plasma membrane	Cell membrane
Definition	Is a semi-permeable barrier that encapsulates individual organelles in a cell or an entire cell	Is a semipermeable membrane that surrounds the entire cell and its contents, including the cytoplasm and all the organelles
Structure and Composition	Structure and composition may vary depending on which organelle it surrounds and that organelle’s requirements	Composed of a phospholipid bilayer embedded with integral proteins that span the membrane, providing pathways for the movement of molecules through the membrane
Role in protecting again invaders	Does not play a protective role	Plays a role in protecting the cell from viral and bacterial invasions
Role in maintaining tonicity	Does not play a role in maintaining tonicity	Plays a role in maintaining correct tonicity
Functions	Exact functions may vary depending on which organelle it is surrounding; Providing a selectively permeable barrier between organelles and cytoplasm	Protecting the cell from outside invaders such as bacteria and viruses; Regulating tonicity of cellular contents; Providing a selectively permeable barrier; Assists in signal transduction mechanisms at the cell surface
Feeding and movement	Are not modified in any way; cilia may not be present	May be modified in some organisms to facilitate movement and feeding; cilia may be present
Signal transdution	Do not contain initial receptors for signal transduction mechanisms	Contains the initial receptors for signal transduction mechanisms
Role in cytokinesis	Do not play a role in cytokinesis	Play a role in cytokinesis during cell division

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