Why is the cell membrane fluid?

1 Answer
Jun 20, 2018



Cell membrane is fluid because individual phospholipid molecules and proteins can diffuse within their monolayer and thus move around.

The fluidity is affected by:

  1. The length of the fatty acid chain. Here, the shorter the chain the more fluid is the membrane.

  2. The saturation of the fatty acids. The more unsaturated fatty acids there are, the more fluid is the membrane, because it causes a kink which makes them fit more loosely.

  3. Cholesterol. The more cholesterol there is the more fluid is the membrane.