Membrane proteins Flashcards
What are the tails of a lipid bilayer described as?
hydrophobic
what are the heads of a lipid bilayer described as?
hydrophilic
what are integral proteins?
proteins on the outer or inner surface of the membrane
what are examples of integral proteins
channel proteins, receptors and transporter proteins
what do peripheral proteins have fewer of compared to integral proteins?
hydrophobic R groups interacting with the bilayer
how are peripheral proteins held in place?
charged or polar amino acids R groups or hydrophobic interactions
Describe facilitated diffusion
passive transport of substance across the membrane through specific transmembrane proteins
describe active transport with conformational change
requires energy from hydrolysis ATP
eg. sodium potassium pump
describe carrier proteins
active transport
conformational change to release proteins
describe channel proteins
facilitated diffusion
doesn’t require a conformational change
what are gated channel proteins?
some channels are gated and respond to a stimulus to allow a conformational change to allow or prevent diffusion
controlled by the binding of signalling molecules
what are voltage channel proteins
a different of voltage respond to a stimulus
conformational change to open/close
controlled by ion concentration
what do regions of hydrophobic R groups allow?
strong hydrophobic interactions that hold integral membrane proteins proteins within the phospholipid bilayer
what are some integral membrane proteins also known as?
transmembrane proteins
what do peripheral membrane proteins have on their surface and what are they bound to?
hydrophilic R groups and
bound to surface membranes by ionic and hydrogen bond interactions
