Unit 1.3 Flashcards
what holds internal membrane proteins within the phospholipid bilayer?
Regions of hydrophobic R groups allow strong hydrophobic interactions that hold integral membrane proteins within the
phospholipid bilayer
What do integral membrane proteins interact with?
Integral membrane proteins interact extensively with the hydrophobic region of
membrane phospholipids.
What are some integral proteins?
Some integral membrane proteins are transmembrane proteins
What do peripheral membrane proteins have and what are they bound to?
Peripheral membrane proteins have hydrophilic R groups on their surface and are bound to the surface of membranes, mainly by ionic and hydrogen bond interactions
What do many peripheral membrane proteins interact with?
Many peripheral membrane proteins interact with the surfaces of integral membrane
proteins
What is the phospholipid bilayer a barrier to?
The phospholipid bilayer is a barrier to ions and most uncharged polar molecules
How to small molecules pass through the bilayer?
Some small molecules, such as oxygen and carbon dioxide, pass through the bilayer by simple diffusion
What is facilitated diffusion?
Facilitated diffusion is the passive transport
of substances across the membrane through
specific transmembrane proteins
What do different cell types have that allows them to carry out specialised functions?
To perform specialised functions, different
cell types have different channel and transporter proteins
What are ligand-gated and voltage-gated channel controlled by?
Ligand-gated channels are controlled by the
binding of signal molecules, and voltage gated channels are controlled by changes in
ion concentration
What must some channel proteins do in order to allow or prevent diffusion?
Some channel proteins are gated and change conformation to allow or prevent diffusion
What are transporter proteins?
Transporter proteins bind to the specific substance to be transported and undergo a
conformational change to transfer the solute
across the membrane
What kind of protein does active transport use?
Active transport uses pump proteins that transfer substances across the membrane against their concentration gradient
What pumps mediate active transport?
Pumps that mediate active transport are transporter proteins coupled to an energy
source.
What source is required for active transport?
A source of metabolic energy is required for active transport
