Chapter 5: Membrane Structure And Transport Flashcards
what is the plasma membrane structure?
phospholipid bilayer
cholesterol
proteins
what are the two proteins in the plasma membrane?
integral and peripheral
what is integral membrane protein?
protein all the way through the membrane
what is the peripheral membrane protein?
proteins attached on the outside of the membrane. they are attached by bonds that are easily broken
cholesterol is a steroid which is a type of
Lipid
what can peripheral membrane proteins attached to?
outside or cytoplasm and use h bonds or ionic bonds
cholesterol is inserted into the membrane so the 4 rings are next to the
fatty acid chains
what does cholesterol give to the plasma membrane?
mechanical strength and maintains fluid because it has to be stiff enough to be a barrier but loose enough to move
what are the 3 types of PM proteins?
peripheral
integrated
glycoproteins
embedded in the phospholipid bilayer of pm
integral
how can you remove integral membrane proteins?
destroy the membrane
what are glycoproteins and location?
integral membrane proteins with sugars covalently attached to
part of protein with the sugar is located in the surface of the pm
will glycoproteins ever be found in the cytoplasm surface?
no
what proteins are used to mark cells?
glycoprotein
what are the functions of pm?
compartmentation- different jobs done in the cell. you put all enzymes need in that specific membrane
communication- with other cells and environment
transport
what separates the living cell from the external environment?
Pm
what is differently permeable?
membranes- only certain molecules can pass through it
why does the lipid bilayer make a good barrier?
it’s hydrophobic
most chemicals in cell are hydrophilic so the can’t dissolve in hydrophobic areas
most salts and biological are
hydrophilic
what can’t hydrophilic molecules pass through?
hydrophobic layer
what can’t sugars pass through by themselves?
lipid bilayer
what substances can pass through a membrane without a transport protein?
substances that are pliable in the hydrophobic part of the lipid bilayer
what molecules can pass through the pm?
water
small, uncharged (O2, CO2)
hydrophobic molecules (steroids)
what molecules can’t pass through the pm?
charged ions
charged molecules
Large macromolecules
polar organic molecules (glucose)