Chemical composition of the plasma membrane
The plasma membrane, in general, is made up of lipids, proteins and, to a lesser extent, carbohydrates.
The plasma membrane, in general, is made up of lipids, proteins and, to a lesser extent, carbohydrates.
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They form the structure of the lipid bilayer. They include:
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The lipids are not arranged in the same way in each of the two layers, so it has an asymmetrical arrangement .
As we have already said, the membrane is not a static structure, but the phospholipids have a certain movement, which gives the membrane fluidity.
The movements that lipids can perform are:
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The fluidity of the membrane by having these movements allows it to repair itself (if it breaks), to fuse with any other membrane, or by endocytosis, to form a vesicle from the membrane.
The main factors that determine the fluidity of the plasma membrane are:
They provide the membrane with its specific functions and are characteristic of each species. Like lipids, they also have lateral diffusion movements, which gives the membrane greater fluidity. Most proteins are globular in structure. There are two kinds:
Membrane proteins are involved in the exchange of substances.
Located on the outer side of the membrane, they intervene in cell recognition functions. They are attached to lipids or proteins forming glycolipids and glycoproteins.
Carbohydrates constitute the glucocalyx, a secretion membrane in animal cells made up of two layers: one, next to the plasma membrane with an amorphous texture, and the other, external, with a fibrous appearance and variable thickness.
Each face of the plasma membrane has a different chemical composition, which is why it is said that the membranes are asymmetric, being able to distinguish the inner and outer face of the membrane by its composition.
Chemical composition of the plasma membrane:
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