Cell Physiology - Topic 2 Slides Flashcards
What are the 3 types of Endocytosis?
- Phagocytosis
- Pinocytosis
- Receptor-mediated endocytosis
What is Vesicular Transport?
Using vesicle to move substance into or out of the cell
What do substance bypass when using Vesicular Transport?
Substances do not need to cross the plasma membrane but instead use vesicles formed by the plasma membrane
What are Vesicles composed of?
Phospholipids and may contain proteins
What is Endocytosis?
A form of vesicular transport which used vesicles to bring molecules into the cell
What is Phagocytosis?
When cells engulf bacteria or large particles such as cell debris from damaged tissue
What is another name for Phagocytosis?
Cell Eating
What occurs in Phagocytosis?
A large particle is surrounded by pseudopodia and folds around the surface of the particle engulfing it completely and pinches off from the cell membrane within the cell
What is a Vesicle in Phagocytosis called?
A Phagosomes
After Phagocytosis occurs what happens to the Phagosome?
It fuses with the lysosome in the cell
What occurs after the Phagosome fuses with the Lysosomes in the cell?
The lysosome digests the contents of the phagosome with digestive enzymes
Which cells use Phagocytosis the most?
Macrophages of the immune system
What is another name for Pinocytosis?
Cell drinking
What occurs in Pinocytosis?
The membrane of the cell invaginates forming a pock with material from the cell exterior bringing things in via a vesicle
What is the specificity of Pinocytosis?
It is non specific
What can pinocytosis take in?
Ions or Nutrients
What is the specificity of Receptor Mediated Endocytosis?
It has high affinity so it very specific
What is the first step in Receptor Mediated Endocytosis?
A receptor on the cell membrane binds with high affinity to a ligand
What occurs after a ligand binds to a receptor in Receptor Mediated Endocytosis?
Clathrin is recruited to the membrane and links to the receptor ligand complex
What does the Receptor, Ligand and Clathrin form?
A cage like structure
What does the cage-like structure of the receptor, ligand and clathrin lead to?
The accumulation of receptor ligand complexes in a localized region of the membrane
What occurs after the accumulation of receptor, ligand and clathrin at the membrane?
The membrane indents forming a coated pit
What is the Coated Pit known as after it pinches off?
A Coated vesicle
What occurs after the Coated vesicle enters the cell?
It loses its Clathrin coat which is recycled