proteins involvement in transport

usually i read that there are 2 types of proteins that help in transport: channels and carriers. However,sometimes in the textbook,they mention 'pores' ...so are pores and channels the same thing? If not,whats the difference between the 3 of them? im confused. Thanks

Reply 1

sea urchin

A channel is a pore. Channels, while they can be selectively permeable i.e only let in one type of substance, allow things to diffuse down their concentration gradient and require no energy. Carriers on the hand usually require energy to transport things against their concentration gradient.

Reply 2

nexttime

There are aquaporins which enable water to pass through the membrane - maybe its that?

Reply 3

sarah99630

Okay thank you for explaining, oh and some carriers don't need energy, the ones that transport substances down their concentration gradients, thanks!!

Original post by sea urchin