membrane fluidity: fusion and formation of vesicles Flashcards
What are vesicles?
Small, spherical sacs made of membrane containing fluid, used for transport and dynamic processes in cells.
How are vesicles formed?
Membrane fluidity allows vesicle formation by pinching off a region of the membrane, a process driven by ATP-powered proteins.
What is endocytosis?
The process where vesicles are formed by inward pinching of the membrane, taking in material from outside the cell, including water, solutes, and large molecules.
What is phagocytosis?
A type of endocytosis where phagocytes (like immune cells) engulf pathogens or particles.
Give examples of endocytosis.
- In placenta, maternal antibodies are absorbed into the fetus.
- Amoeba engulfing food particles.
- Phagocytes ingesting pathogens.
What is the role of vesicles in intracellular transport?
Vesicles move materials inside cells, such as transporting proteins from the RER to the Golgi apparatus for processing.
What is exocytosis?
The process where vesicles fuse with the cell membrane to expel contents outside the cell, such as waste or useful products like enzymes and hormones.
How do vesicles contribute to cell membrane expansion?
In growing cells, vesicles help increase membrane surface area by fusing with the membrane, bringing in phospholipids and membrane proteins.
