Membranes Flashcards
What is the framework of a membrane?
The phospholopid bilayer
Phospholipids are…
amphipathic molecules
Amphipathic is…
having both hydrohilic and hypdrophobic parts
What is hydrophobic?
Disliking of water
What is hydrophilic?
The liking of water
fatty-acid tails are…
hydrophobic
glycerol heads are…
hydrophilic
Membranes also contain…
proteins and carbohydrates
Leaflets:
halves of the bilayer
The leaflets are…
asymmetrical to one another with different amounts of each component
What is the membrane considered?
A moisac of lipids, proteins, and carbohydrates molecules
Membrane resembles a fluid because…
lipids and proteins can more relative to each other within the membrane
Transmembrane Proteins are…
Physically embedded in the hydrophobic portion of the phospholipid bilayer
Lipid-anchored proteins
Amino acid, of protein, convalently linked to a lipid
Integral Membrane Proteins are
a type of protein that is permanently attached to the membrane
Intrinsic Membrane Proteins are
embedded in the lipid bilayer so that the polypeptides come in contact with the non-polar region of the bilayer
What is a polypeptide?
A large number of amino-acid residues bonded together in a chain
Peripheral or Extrinsic Membrane Proteins are
Non-covalent bounded , to intergral membrane proteins that project out from the membrane or lipid head
What is Peripheral?
a class of membrane proteins that attach to the lipid bilayer, acting on the lipid-water interface
Extrinsic…
are entirely outside of the membrane, but are bound to it by weak molecular attractions
Membranes are semi…
fluid
Most lipids can rotate freely around…
their long axis and move laterally within the membrane leaflet
“Flip-flop” of lipids from one leaflet to another requires…
ATP and the enzyme, flippase
Lipid rafts are formed when…
Certain lipids aggregate strongly with one another
