Endocytosemiexocytoseare examples of bulk transportmechanisms in cells🇧🇷 The differences and similarities between endocytosis and exocytosis will be discussed in this article.
These mass transport mechanisms are used to move materials in or out of the cell. The processes function to transport molecules and substances that are too large to pass directly through the lipid bilayer of thecell membrane.
Index
- What is endocytosis and exocytosis?
- Definition of endocytosis x exocytosis
- What is endocytosis?
- The process of endocytosis.
- intussusception
- vesicle formation
- detachment
- The process of endocytosis.
- What is exocytosis?
- The process of exocytosis
- What is endocytosis?
- endocytose x exocytose diagram
- Examples of Endocytosis vs Exocytosis
- What is the difference between endocytosis and exocytosis?
- How are endocytosis and exocytosis similar?
- Similarities of endocytosis and exocytosis.
- Phagocytose x endocytose x exocytose
What is endocytosis and exocytosis?
Endocytosis and exocytosis are types of mass transport that require energy expenditure (ATP) to move substances into or out of the cell, respectively. Therefore, they are active transport processes. Some of the substances that move across the cell membrane through these processes include large molecules, waste products, and microorganisms.
The cell membranes of organisms are semi-permeable and therefore allow certain small molecules and ions to passively diffuse through them. However, some molecules cannot pass through theplasma membranefrom a cell or move through a transport protein because they are so large. Because of this, cells use two active transport processes (endocytosis and exocytosis) to move these macromolecules into or out of the cell.
For example, there are times when a cell will need to release a hormone or swallow abacteria🇧🇷 In such cases, bulk transportation arrangements are required. Endocytosis and exocytosis are the mechanisms used in these cases. Therefore, endocytosis and exocytosis are means of transport used byeukaryotes.
Definition of endocytosis x exocytosis
Endocytosis involves theactive transport of moleculesinside the cell, surrounding it with its membrane, while exocytosis pushes molecules out of the cell.
In living systems, the need forhomeostasiscauses an equal flow of molecules into and out of the cell. Therefore, the number of molecules that enter the cell by endocytosis is equal to the number of molecules that leave the cell by exocytosis. In other words, the two main categories of vesicle transport are endocytosis and exocytosis.
What is endocytosis?
Endocytosis is a cellular process by which cells ingest materials into the cell. The material or substance that is introduced into the cell is surrounded by an area of ​​cell membrane that then sprouts within the cell to create a vesicle that contains the ingested substance. This means that endocytosis moves materials into a cell through membrane vesicles.
There are four known types of endocytosis, including:
- phagocytosis
- pinocitosis
- Receptor-mediated endocytose
- cavaolas
The process of endocytosis.
Endocytosis transports materials from the external environment of the cell into the cell. During the process of endocytosis, the plasma membrane (cell membrane) folds around the material to be swallowed. This results in the formation of a vesicular structure that eventually detaches from the membrane within the cell. Therefore, the process of endocytosis in cells involves steps that include the following:
- intussusception
- vesicle formation
- detachment
intussusception
This is the first of the steps of endocytosis, which involves the folding of the cell membrane and the creation of a cavity in which the material to be engulfed is trapped.
vesicle formation
The next step is the folding of the cell membrane to form a vesicle with a uniform vesicle membrane thickness. This formed vesicle contains the material to be swallowed.
detachment
After vesicle formation, the vesicle separates from the cell membrane. The vesicle then proceeds to its further processing by the cell.
What is exocytosis?
Exocytosis is a process by which cells move materials that are inside the cell, out of it, and in the extracellular fluid. The exocytosis process occurs as a result of the fusion of a vesicle with the plasma membrane that allows the release of its contents outside the cell.
Exocytosis can be defined asbiologyas the process by which cytoplasmic secretory vesicles fuse with the cell membrane to release their contents into the extracellular space. Through exocytosis, neurotransmitters are released from the synaptic vesicles into thesynaptic cleft🇧🇷 Cells use exocytosis to transport substances from the inside of the cell to the outside of the cell.
There are basically three types of exocytosis which include:
- constitutive exocytose
- regulated exocytose
- lysosome-mediated exocytosis
The process of exocytosis
During exocytosis, membrane-bound vesicles containing cell molecules are transported to the cell membrane. The vesicles then fuse with the cell membrane and expel their contents out of the cell. Therefore, the process of exocytosis involves the use of energy to transport molecules such as neurotransmitters and proteins out of the cell.
It is a form of mass transport because a large number of molecules are released. This process occurs through secretory portals in the plasma membrane of the cell calledporosomos🇧🇷 Porosomes are cup-shaped permanent lipoprotein structures located in the plasma membrane of the cell. Secretory vesicles dock and transiently fuse at these porosomes to release the intravesicular contents of the cell. These are the steps that occur during exocytosis:
- A vesicle forms inside theendoplasmic reticulummiGolgi apparatusor early endosomes.
- Vesicles containing molecules travel inside the cell to the plasma membrane (cell membrane).
- The vesicle membrane fuses with the plasma membrane, and the two bilayers fuse together.
- This fusion causes the contents of the vesicle to be released into the extracellular space (outside the cell).
- The vesicle then fuses with or separates from the plasma membrane.
Listed above are the five basic processes that occur during exocytosis, includingvesicle trafficking, vesicle tethering, vesicle docking, vesicle priming, and vesicle fusion🇧🇷 In constitutive exocytosis, four of these processes occur, while the full five steps occur in regulated exocytosis.
endocytose x exocytose diagram
The image above is a simple diagram of endocytosis vs. exocytosis showing the difference in their process.
Examples of Endocytosis vs Exocytosis
The following table shows some examples to compare and contrast endocytosis and exocytosis.
Examples of endocytosis | Examples of exocytosis | |
1 | Phagocytosis in immune cells To neutralize and eliminate pathogenic material from the body, immune cells, such as dendritic cells, macrophages, and neutrophils, exhibit phagocytosis, for example, white blood cells engulfing a bacterium. | exocytosis in the pancreas Small groups of cells in the pancreas calledIslets of Langerhansproduce the hormones glucagon and insulin that are stored in secretory granules. These hormones are then released by exocytosis when signals are received. This is a typical example of exocytosis in the human body. |
2 | Pinocytosis in cells The absorption of nutrients, hormones and enzymes by cells occurs through pinocytosis. For example, cells in the body absorb hormones andenzymesvia pinocytosis. Human ova and microvilli cells in the intestines also take up nutrients from the surrounding environment by pinocytosis. | exocytosis in neurons One of the examples of exocytosis is synaptic vesicle exocytosis that occurs in neurons of the nervous system. Nerve cells interact and communicate through chemical (neurotransmitters) or electrical signals that pass from one neuron to another. Through the transmission of neurotransmitters, some neurons communicate. |
What is the difference between endocytosis and exocytosis?
The difference between endocytosis and exocytosis involves the movement of substances into or out of the cell, respectively. In endocytosis, substances and materials are transported from the outside of the cell to the inside of the cell. Whereas, in exocytosis, the substances or materials inside the cell are moved and transported to the outside of the cell. However, both of these processes are forms of active transport because they require energy.
What is the difference between endocytosis and exocytosis? Let's use a table to compare and contrast endocytosis and exocytosis.
Comparison factors | ENDOCYTOSE | EXOCITE |
Definition | This process involves moving a particle or substance from outside the cell and transferring it into the cell via a vesicle. | This process involves moving a substance or particle from inside the cell and out of the cell using a vesicle. |
types | (1) phagocytosis | (1) Constitutive exocytose |
How it works | An endocytic vesicle forms surrounding the foreign substance. | The vesicle containing the residue or substance fuses with the plasma membrane. |
Types of Vesicles Formed | Internal vesicles are formed, such as phagosomes. | Secretory vesicles are formed. |
occupation | (1) Absorption of nutrients for cell function | (1) Elimination of toxins or waste |
examples | White blood cells engulfing a virus and eliminating it is an example of endocytosis. | The release of a neurotransmitter for cell communication is an example of exocytosis. |
The above tabular presentation summarizes the difference between endocytosis and exocytosis.
How are endocytosis and exocytosis similar?
Endocytosis and exocytosis are means of transport used by eukaryotic cells. Regardless of the differences in function between endocytosis and exocytosis, they are similar in that the main process underlying both processes involves the cell membrane forming an invagination, or pouch, as well as involving the underlying substance that must be transported into it. of the cell. Furthermore, both processes require energy.
Similarities of endocytosis and exocytosis.
- Both mechanisms are forms of active transport.
- Both use energy to transport particles into or out of the cell.
- These processes have different types that are similar in that both transport materials across the cell membrane by forming porous vesicles.
Phagocytose x endocytose x exocytose
Endocytosis and exocytosis are examples of bulk transport mechanisms in cells, whilephagocytosisIt is a type of endocytosis. The comparison of phagocytosis vs. endocytosis vs. exocytosis is that phagocytosis is a type of endocytosis whereas endocytosis involves the movement of solid or fluid materials into the cell through the formation of vesicles on the cell membrane. Exocytosis, on the other hand, involves the movement of materials out of the cell into the extracellular environment.
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