Pinocytosis

Definition

Pinocytosis is a type of endocytosis where the cell engulfs extracellular fluid, including dissolved solutes. This process allows cells to intake nutrients and other necessary molecules from their environment.

5 Must Know Facts For Your Next Test

1. Pinocytosis is often referred to as 'cell drinking' since it involves the uptake of liquid.
2. It is a nonspecific process, meaning that cells do not selectively choose which molecules to ingest.
3. During pinocytosis, small vesicles form by invagination of the cell membrane.
4. This process requires energy in the form of ATP, classifying it as an active transport mechanism.
5. Pinocytosis helps maintain cellular homeostasis by regulating the internal fluid environment.

Review Questions

• What distinguishes pinocytosis from other forms of endocytosis?
• Why is pinocytosis considered a nonspecific process?
• How does pinocytosis contribute to cellular homeostasis?

Related terms

Endocytosis: The general process by which cells engulf external substances through their membrane.

Phagocytosis: A specific type of endocytosis where cells ingest large particles or entire microorganisms.

Exocytosis: The process by which cells expel materials in vesicles to the exterior of the cell.