Endocytosis and Exocytosis (Endocytosis vs Exocytosis)

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Last Updated on May 1, 2020 by Sagar Aryal

Endocytosis and Exocytosis (Endocytosis vs Exocytosis)

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Similarities of Endocytosis and Exocytosis

  1. Endocytosis and exocytosis mechanisms are forms of Active Transport, both using energy to transport particles in and out of the cell.
  2. They both have different types similar in that they both transport materials across the cell membrane by forming vesicle pores.

Differences between Endocytosis and Exocytosis

Characteristic

Endocytosis

Exocytosis

Definition

Endocytosis is a cellular mechanism where a cell internalizes substances from the external environment. These substances undergo certain processes of breaking down to smaller elements either for use by the cell or for elimination purposes.Exocytosis is a process that is used to transport materials from inside the cell to the external part of the cell by the use of energy. The mechanism uses special vesicles fille with the particles of interest to transport Generally, in this mechanism of exocytosis,  a special vesicle bound to the cell membrane, containing the cellular particles will expel the cell content to the external part of the cell.

Types

There are three types based on the mechanisms of particle. They include:
  • Phagocytosis
  • Pinocytosis
  • Receptor-mediated endocytosis (Clathrin-mediated endocytosis)
There are also 3 types depending on the sequence of processes involved in transporting particles out of the cell. They include:
  • Constructive Exocytosis
  • Regulated exocytosis
  • Lysosome mediated Exocytosis

Energy

  • Being a form of active transport, they use some energy (ATP) during particle transportation.
  • It is a type of active transport, using a lot of energy (ATP) for transporting particles out of the cell.

Functions

Endocytic mechanisms are used to:
  • Breakdown and eliminate microbial antigens using phagocytic cells
  • Protozoans such as amoeba use phagocytosis to trap and digest nutrients (food)
  • Uptake and absorption of nutrients through intestinal villi in the small intestines
  • Transportation of iron-transferrins in receptor-mediated endocytosis
  • To absorb cholesterol that is bound to ‘bad cholesterol’ (Low-density lipoproteins) in receptor-mediated endocytosis
Exocytosis is known for its functions in:
  • Transportation of proteins and lipids use to repair the cell membrane after endocytosis
  • Transportation of glucagon and insulin hormones from the pancreas to the liver for breakdown and utilization by the body depending on body sugar levels.
  • Transportation of chemical signals between cells allowing cell communication
  • It is also important in synaptic transmission of information in the neurons

References and Sources

  • https://microbenotes.com/endocytosis-definition-process-and-types-with-examples/
  • https://microbenotes.com/exocytosis-definition-process-and-types-with-examples/
  • https://socratic.org/biology/movement-in-and-out-of-cells/transport-across-the-cell-membranes
  • https://www.thoughtco.com/what-is-exocytosis-4114427
  • https://quizlet.com/333668107/active-transport-flash-cards/
  • https://pediaa.com/difference-between-endocytosis-and-exocytosis/

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