9 Facts On Endocytosis Molecular Movement: What Types, How, When


Endocytosis molecular movement entails transport of substances from cell surface to the interior of the cell. Endocytic pathways can help cells take up specific nutrients like, LDL; it also helps cells to remove surface receptor proteins and extracellular ligands selectively.

Endocytosis molecular movement is generally of two types, i.e., Bulk-phase endocytosis and receptor mediated endocytosis

Types of molecules transported in endocytosis:

Large molecules, that are unable to be transported through membrane transport proteins, are generally transported through endocytosis. E.g., cholesterol, iron atoms carried by iron binding proteins etc. It also transports membrane proteins. In case of immune system, endocytosis molecular movement transports foreign antigens and triggers immune response.

What happens in endocytosis?

In endocytosis molecular movement, plasma membrane along with membrane proteins and bound ligands bud inwards and forms endocytic vesicles. After being internalized by endocytic vesicles some proteins are recycled and reintroduced to the secretory pathway; while others are transported to lysosome to be degraded via late endosomes.

What does endocytosis use to move molecules?

Endocytosis molecular movement uses endocytic vesicles to move molecules. Endocytotic vesicles or vacuoles are formed by inward extension of cell membrane, which engulfs extracellular substances and captures them by completing vesicle formation.

How does endocytosis work?

In case of bulk-phase endocytosis, molecules are taken in indiscriminately by cell through the uptake of extracellular fluids. This process is also known as pinocytosis.

Receptor-mediated endocytosis is generally done by clathrin/AP2 coated pits and the ligands are packaged in a process similar to that of a vesicle formation at the trans golgi network.

Does endocytosis move water?

Bulk-phase endocytosis intakes and moves extracellular fluids via endocytic vesicles.

Does endocytosis move through the phospholipid bilayer?

Endocytosis is the process of capturing extracellular substances and engulfing them inside the cells. So of course, we can say that endocytosis moves through phospholipid bilayer. Cell plasma membrane itself shows invagination and form vesicles by protruding inward during endocytosis molecular movements.

Does endocytosis move substances in vesicles?

Endocytosis molecular movements transport various substances in vesicles that are called endocytic vesicles. These vesicles eventually fuse with late endosomes, which in turn merges with lysosomes or get involved in trans golgi network for further processing.

When does endocytosis occur?

Endocytosis molecular movement is triggered by various ligands like hormones, growth factors, enzymes etc. binding with cell surface receptors and proceed with cellular intake. The ligands bind with specialized domains on the plasma membrane called coated pits, where the M6P receptors are present. M6P receptors after endocytosis; are recycled and sent back to the cell surface.

It can also be triggered by foreign pathogens and triggers immune response.

What is “cellular drinking?”

“Cellular drinking” or pinocytosis is the process in which cell membrane folds taking in extracellular fluids and dissolved substances. They create pinocytotic vesicles which then fuse with early endosomes.

Pinocytosis sometime takes in protein molecules too and known as potocytosis.

What is “cellular eating”?

“Cellular eating” or phagocytosis is the process of cellular intake of large particles by triggering cellular receptors and creating pseudopodia to engulf the extracellular particles. Phagocytotic vesicles fuse with lysosome for further processing.

endocytosis molecular movement
Fig: “File:Phagocytosis2.png” by Graham Colm Talk is licensed under CC BY-SA 3.0.

How does endocytosis help in immune system?

In case of macrophages, neutrophil, or antigen presenting cells, they perform phagocytosis to capture pathogens or foreign antigens.

Conclusion:

Process of endocytosis, i.e., engulfing extracellular substances and transporting to cytoplasm is imperative for nutrient intake, cellular maintenance and even for immune system.

Pratyush Das Sarma

Hi.....I am Pratyush Das Sarma, I have completed my Master's in Biotechnology. I always like to explore new areas in the field of Biotechnology. Apart from this, I like to read and travel.

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