Question

In what way is membrane fluid?

Answer 1

Membrane fluidity refers to the lateral movement and flexibility of proteins and lipids within the cell membrane, essential for transport, signaling, and maintaining homeostasis. The fluid mosaic model illustrates this, while factors like lipid unsaturation and temperature can affect fluidity.

Step-by-step explanation:

In biological terms, membrane fluidity refers to the flexibility of the cell membrane, which is an essential property for maintaining cellular function and integrity. The fluid characteristic of a cell membrane is attributed to the fluid mosaic model where integral proteins and lipids are not rigidly fixed in place, but rather float and move laterally within the membrane, much like buoys in water. This fluid nature allows for the components of the membrane to change position and adapt to various conditions, which is critical for processes like transport of substances in and out of the cell, signaling, and interacting with external environments to maintain homeostasis.

Cell membranes are not infinitely flexible, as they can burst if overly stretched or penetrated by a foreign object. However, the ability of the membrane to self-seal after being penetrated by a fine needle demonstrates its remarkable fluidity. Furthermore, membrane fluidity is affected by factors such as the degree of unsaturation in the hydrocarbon tails of the lipids and environmental temperature, both of which can alter the fluid nature of the membrane to ensure proper physiological functioning.

Answer 2

Cell membranes are comprised of phospholipids which are loosely attracted to each other by van der wahl forces and hydrogen bonding. That means they are able to individually respond to the environment and water by their hydrophillic and hydrophobic properties. This individual response is why cell membranes are 'fluid'.