Movement Of Molecules Across Membranes Flashcards
What do regions of hydrophobic R groups allow ?
Strong hydrophobic interactions that hold integral membrane proteins within the phospholipid bilayer
What are some integral membrane proteins?
Transmembrane proteins
What do peripheral membrane proteins have?
Hydrophilic R groups on their surface
Where are peripheral membrane proteins bound ?
To the surface of membranes
How are peripheral membrane proteins bound ?
Mainly by ionic and hydrogen bond interactions
What do many peripheral membrane proteins interact with ?
The surfaces of integral membrane proteins
What does the phospholipid bilayer do ?
It is a barrier to ions and most uncharged polar molecules
What can pass through the bilayer through simple diffusion ?
Small molecules such as oxygen and carbon dioxide
What is facilitated diffusion ?
The passive transport of substances across the membrane through specific transmembrane proteins
What do different cell types have , to preform specialised function ?
Different channel and transporter proteins ?
Most channel proteins in animal and plant cells are what ?
Highly selective
Why are some channel proteins gated ?
To change the conformation to allow or prevent diffusion
What are ligand-gated channels controlled by?
The binding of signal molecules
What are voltage-gated channels controlled by?
By changes in ion concentration
Why do transporter proteins bind to specific substance?
To be transported and undergo a conformational change to transfer the solute across the membrane
