Facilitated Diffusion Flashcards
1
Q
What is facilitated diffusion?
A
the passive movement of molecules across the cell membrane via a specific transmembrane protein
2
Q
What are the two types of transmembranes used in factilitated diffusion?
A
protein channel (closed)
carrier protein ( open)
3
Q
What are the features of protein channel molecules?
A
small, charged (polar) molecules e.g. ions such as Na+ , K+, Ca2+
4
Q
What are the features of carrier proteins?
A
large molecules
e.g. think of it as an aircraft carrier - big boat and big planes land
5
Q
What do both transmembranes have in common?
A
high -> low concentration (diffusion)
specific to each molecule that has its own transport protein
the same proteins can be used for active transport (against concentration gradient using ATP)
