Chemical Transport & Cell Membranes?
What are the three other mechanisms (besides osmosis) when talking about chemical transports across cell membranes?
and also, what is the driving force for each of the three mechanisms? and do they require a carrier and/or energy?
Answers & Comments
Verified answer
There are two main forms - active transport and passive transport. Passive transport refers mostly to osmosis, but in some cases a type called passive cotransporting occurs in which a protein channel exchanges something like 2 Na+ out for 1 K+ in. Another type is a ligand-gated ion channel which will allow the flow of ions to occur once an appropriate molecule binds to and activates it. A third form of transport (falling under active transport) would be an ATP mediated pumping channel... which will basically use energy to push an ion or molecule against its gradient.
There are much more forms of transmembrane transport systems but I think these will do for your answer.