Cell Membrane Flashcards
Describe 3 functions of the cell membrane
controls the movement of substances in and out of the cell, provides mechanical support to the cell (helps maintain the shape of the cell) and is a receptor for chemical materials.
The cell membrane is selectively permeable. What does this mean?
It will only allow certain molecules in and out of the cell.
What do integral proteins do?
penetrate part or all the way throughh the membrane.
Peripheral proteins…
are weakly bound to the cell membrane or other proteins.
What is the role of protein channels?
To act as carrier molecules. They are also hydrophilic and allow large or water soluble molecules to be transported across the membrane.
Glycoproteins are..
proteins or lipids that have branching carbohydrate portions on their free surfaces. They are made up of sugar molecules. They support the immunological response.
Where is cholesterol found?
Between the phospholipid molecules in the bilipid layer
What is the role of cholesterol?
To regulate the fluidity of the membrane.
Which form of transport requires energy?
Active Transport
Explain the difference between active and passive transport.
Active transport requires energy while passive transport does not. Active transport also goes against the concentration gradient.
What is exocytosis
active movement of materials out of cells.
What is endocytosis
active movement of materials into the cell- is a form of active transport that usually moves large polar molecules that cannot pass through the hydrophobic cell membrane into the cell
What is facilitated diffusion?
where molecules are assisted in moving from high conc to low conc.
Which process involves the movement of water molecules across a selecitvely permeable membrane from low to high conc.
Osmosis
What is the fluid mosaic model?
It explains that the cell membrane is a dynamic structure in which proteins can float.
