With reference to the diagram below explain how channel proteins and carrier proteins carry out facilitated diffusion differently.
science
Description
Cell Biology Formative Assessment
Topic 2
Task
1. With reference to the diagram below explain how
channel proteins and carrier proteins carry out facilitated diffusion
differently.
However,
channel proteins form open pores through the cell membrane, allowing free
diffusion of any molecule of appropriate size and charge. Furthermore, carrier
proteins are responsible for the facilitated diffusion of sugars, amino acids,
and nucleosides across the plasma membranes of most cells. Also, channel
proteins which only transport substances through membranes
passively, carrier proteins can transport ions and
molecules either passively through facilitated diffusion, or
secondary active transport.
Task
2. Describe
how active transport differs from passive transport, and which substance is used
to supply the energy required.
Active
transport requires chemical energy because it is the movement of
biochemicals from areas of lower concentration to areas of higher
concentration. On the other hand, passive transport moves
biochemicals from areas of high concentration to areas of low concentration, so
it does not require energy.
