The Cell Membrane

Cell Membrane

• It defines the cell, outlines its borders, and determines the nature of interaction with its environment.

• It is very flexible to allow certain cells, such as red blood cells and white blood cells, to change shape as they pass through narrow capillaries.

Components and Structure of Cell Membrane

Phospholipid

• The main fabric of the membrane

• It provides the pathways for substances across the membranes

Cholesterol

• Attached between phospholipids and between the two phospholipid layers.

• It dampens the effect of the temperature.

• Hot temperature causes the membrane components to move farther away from each other and the membrane disintegrates, while cold temperature causes the phospholipids to clump together and make the cell membrane too rigid to work properly.

Integral Proteins

• Embedded within the phospholipid layer(s). It may or may not penetrate through both layers.

• It transports substances through a membrane.

Peripheral Proteins

• It’s on the inner or outer surface of the phospholipid bilayer; not embedded within the phospholipids

• It’s function is cell recognition

Carbohydrates

• Generally attached to proteins on the outside membrane layer

• Its functions are cell recognition and effective interaction with the aqueous environment