Cell Processes Flashcards
What is the plasma membrane?
A thin flexible and sturdy structure that surrounds the cytoplasm of the cell
What is the PM made of?
50% lipid and 50% protein held together by H bonds
What do the lipids do?
It is the barrier to entry or exit of polar substances
What do the proteins do?
They are gatekeepers to regulate the flow of molecules
What are the 3 types of lipid molecules?
Phospholipids, cholesterol and glycolipids
What are phospholipids?
75% of the lipids. 2 parallel layers. Amphipathic molecules.
What are glycolipids?
Sugar group and membrane-embedded group
What does cholesterol do?
Changes fluidity of the membrane
What does fluidity do?
Determines the properties of the lipid bilayer. Based on the structure of molecules.
What is fluidity determined by?
Lipid length tail- the longer the tail = less fluid
Number of double bonds - more double bonds = more fluid
Amount of cholesterol - more cholesterol = less fluidity
What are integral proteins?
extend into or across PM
What are peripheral proteins?
Attached to the inner or outer surface of PM. can be easily removed
How can peripheral proteins be removed from PM?
Break interactions, expose PM to an ionic solution, change ion strength, break ionic bonds, peripheral proteins can be removed
What are the functions of PM proteins?
Receptor proteins. Cell Identify Markers. Linkers. Enzymes. Ion Channels. Transporters.
What can peripheral proteins do to the PM
Bend/change shape of PM
