Index >>Bacterial Fungal Cells>>Bacterial Cell Membrane

Bacterial Cell Membrane -

Cell membrane is the bounding layer of the cytoplasmic contents and is the principal osmotic and permeability barrier.

It is a lipoprotein (70:30, of protein and lipid) devoid of any polysaccharide and when examined under an electron microscope appears as a three layer unit with a unit membrane structure,

The two outer layers are about 3.5 nm thick and the middle layer is about 5 nm thick.

Lipids found in the cell membrane are phospholipids such as phosphatidylethanol amine and to a lesser extent phosphatidylserine and phosphatidyl choline,

(iii) it contains the components of the energy generation system.

In addition to these, there is also evidence to show that the cell membrane has specific attachment sites for the replication and segregation of the bacterial DNA and the plasmids.

In some bacteria, particularly in the Gram-positive bacteria, defending upon growth conditions the membrane appears to be in folded at more than one point. Such in foldings are called mesosomes.

The presence of such structures in large numbers have also been found organisms that have higher respiratory activity as the nitrogen fixing bacteria namely azobacter or during the logarithmic phase growth.