L20 Endocytosis Flashcards
What is endocytosis?
Endocytosis is a cellular process by which cells take in substances from their external environment.
As if cells are eating/drinking on a microscopic level
What can be taken up in endocytosis? (7)
Nutrients
Signals
Antibodies
Enzymes
Viruses
Bacteria
Membrane
What are the different fates that endocytosed material can have?
Recycling
Transcytosis
Degradation
What are the multiple endocytic pathways?
Small - scale endocytic processes (Clathrin)
Macropinocytosis
Phagocytosis
What are endocytosis pathways? (G= Gemini)
Endocytosis pathways play vital roles in various cellular functions, including nutrient uptake, cell signaling, immune response, and waste removal.
Dysregulation of these pathways can lead to various diseases and disorders.
What is opsonization? And how does it relate to phagocytosis? (G)
Opsonization is a vital process that enhances the ability of the immune system to eliminate pathogens.
By coating foreign particles with opsonins, the body ensures their efficient recognition and destruction by phagocytes.
What is frustrated phagocytosis?
Both phagocytes may attempt to engulf the bacterium, but neither is able to fully internalize it
What was the first hint that membrane recycling occurs with beads? (G and PowerPoint)
The first hint that membrane recycling occurs with beads came from the observation that cells can continuously internalize and degrade large particles like latex beads without significant changes in cell volume.
What’s the difference between macropinocytosis and phagocytosis?
Specificty: M- non specific, P - specific
Particles engulfed: M- Fluid and solutes, P- large particles
Mechanism: Membrane ruffling, P - Membrane end tension
Vesicle size: M- Large, P- small
What does LDL stand for?
Low-Density Lipoprotein
How does Clathrin mediated endocytosis work? (I’ll do this)
Clathrin-mediated endocytosis is a highly regulated and efficient process that plays a crucial role in various cellular functions.
It ensures the selective uptake of essential molecules and the proper functioning of signaling pathways.
What’s the structure of Clathrin? (G)
- Triskelion
- Lattice Formation
This intricate structure of clathrin is essential for its function in driving the formation of vesicles during clathrin-mediated endocytosis.
What’s the similarity of all the 3 endocytic pathways that we need to know? (G)
All 3 have a pinching motion
What is dynamin and what is it required for?
Dynamin acts like a molecular “scissors,” cutting the vesicle free from the cell membrane, allowing the internalized cargo to be transported within the cell.
How does actin relate to the 3 endocytic pathways?
actin is a dynamic and versatile protein that plays a critical role in all three major endocytic pathways.
Its ability to polymerize and generate force, shape membranes, and interact with other proteins makes it an essential component of the endocytic machinery.
Remember Rab5 (make a question on this)
Why is the gradient of pH, key for function of endocytic pathways? (G)
the gradient of pH plays a critical role in regulating various aspects of the endocytic pathway, including cargo sorting, trafficking, enzyme activation, and membrane fusion.
What does MVB stand for?
Multivesicular body (MVB)
