The Importance Of Eukaryotic Plasma Membrane

Plasma membrane is important in eukaryotic cell and it has many internal compartments. It also protects the integrity of the interior of the cell by allowing certain substances in, while keeping other substances out.

Eukaryotic Plasma Membrane

Eukaryotic cells are delimited by the cytoplasmic membrane and contain cytoplasm, ribosomes and DNA. They are also characterized by the presence of internal compartments delimited by the membrane, the organelles, that contain specific enzymes. Among these, there is the nucleus that contains most of the genetic material (DNA) of the cell. Here occur the DNA duplication and the first steps in decoding genetic information.

In all eukaryotic cells, there are also: the endoplasmic reticulum, the Golgi apparatus,

The proteins that carry out the active transport then pump a specific solute through a membrane in the opposite direction to that of diffusion, consuming ATP. The active transport modes through a membrane are three:

• primary active transport - if the transport proteins transfer only one substance in one direction.

• coupled transport - if transport proteins transfer two substances in the same direction.

• Antiporter - if the transport proteins transfer two substances in opposite directions, one towards the inside and the other towards the outside of the cell.

As a result, the main differences among the different type of diffusion and transport is that free diffusion and facilitated diffusion does not need energy and their driving force is the gradient of concentration, the only difference between the two is that the facilitated diffusion needs a membrane protein. Active transport, instead, needs energy and a membrane protein. Plus, its driving force relies on the hydrolysis of ATP (against

This can occur through vesicles that are formed by throttling the plasma membrane and then penetrating into the cell (endocytosis), or they merge with it to free their contents (exocytosis) outside. There are three types of endocytosis known:

• phagocytosis - very common among unicellular protists, who use it to feed themselves; in the human body, some types of white blood cells incorporate cells and foreign substances into phagocytosis.

• pinocytosis - a constant activity of pinocytosis is carried out by the endothelium, the tissue that covers the blood capillaries and which allows the cells of the surrounding tissues to withdraw fluids from the blood.

• Receptor-mediated endocytosis - a quick and efficient method for withdrawing substances that can be found in the environment even at low concentrations.

Finally, exocytosis is important for the secretion of many substances, including digestive enzymes produced by the pancreas and materials for the construction of the plant cell wall.