The Membrane Flashcards
What type of molecules are phospholipids?
Amphipathic (having a hydrophobic and hydrophilic end to interact with both polar and nonpolar substances.)
What is the fluid mosaic model described as being?
Membrane is fluid with a mosaic of proteins embedded in it.
Are phospholipids stationary?
No, they are mobile in a lateral phase, but the also flip flop infrequently.
Are phospholipids stationary?
No, they are mobile in a lateral phase, but they also flip flop infrequently.
What are the 5 functions of the cell membrane?
1) (PROTECTION) Enclose and Protect the cell contents
2) (SUPPORT) Provide and support mechanical structures.
3) (TRANSPORT) Transport in & out of the cell
4) (COMMUNICATION) Markers & signaling
5) Metabolic Activities
What is the permeability of the cell membrane?
Selectively Permeable, allowing certain molecules through and blocking others
What is the role of the extracellular matrix?
Interact with cell membrane of adjacent cells.
How is the internal pressure and concentrations of intracellular components maintained?
Through the cell membrane
What does passive transport entail?
Molecules diffusing across the membrane with the concentration gradient (High to Low).
What does active transport entail?
Molecules being pumped across the membrane against a concentration gradient (low to high).
What form of transport requires energy?
Active
What type of molecules can cross through the membrane?
Hydrophobic Molecules such as O2 and CO2.
What type of molecules cannot cross through the membrane unassisted?
Hydrophilic molecules, large molecules and charged ions.
