Chapter 1.4- Membrane Transport Flashcards
What is a vesicle?
A vesicle is a small sac of membrane with a droplet of fluid inside
Are vesicles present in all cells?
They are normally present in eukaryotic cells
There are no vesicles in prokaryotic cells
Which characteristic is important for endocytosis to happen?
The fluidity of the membrane
How does a vesicle form?
To form a vesicle, a small region of a membrane is pulled from the rest of the membrane and is pinched off
Which molecule is responsible to carry out endocytosis
Proteins
What exactly is endocytosis?
It is a method of taking materials into the cell
What substances are usually transported from the outside of the cell to the inside of the cell?
Water and solutes, often contain larger molecules needed by the cell that cannot pass across the plasma membrane
What can be reasons for vesicle movements in cells?
Either the contents of the vesicle or the protein in the membrane of the vesicle
What is an elementary process, in which vesicles are a crucial part?
formation of proteins
What is exocytosis?
Exocytosis is a method to release materials from cells to the outside of cells
What is diffusion?
Diffusion is the spreading of particles in liquids and gases that happens because the particles are in continuous random motion. More particles move from an area of higher concentration to an area of lower concentration than move in the other direction.
In which direction does the movement of diffusion go?
Down the concentration gradient
Which membrane transports are active?
- endocytosis
- exocytosis
- sodium-potassium pump
Which membrane transports are passive?
- simple diffusion
- facilitated diffusion
- osmosis
What is simple diffusion?
Simple diffusion across membranes involves particles passing between the phospholipids in the membrane
