Bio Questions

[Jayward]

Hey guys, im new to the bio thread. (just started u3/4 biol this year and am still in year 11). could somebody please explain something to me?. micelles are produced when phospholipids are placed in an aqueous solution yeah, when the fatty acids are short. BIlayers of phospholipds form when they are placed in aqueous solutions and the fatty acid chains are relatively long. When exactly does a monolayer of phospholipds form?? when the fatty acids are excessively long? its really bugging me. and also, could someone please explain the difference between primary active transport and secondary active transport? i noe that primary A.T. directly involves input from atp and secondary A.T. uses electrochemical potential to proceed, but could somebody please EXPLAIN exactly what all of that means??? thanks guys

[Cookiez]

I'll be able to explain the second part of your question,
Secondary Active transport is in which the diffusion of one molecules down its electrochemical gradient is used to pump a second molecule against ts electrochemical gradient. It's like when something gets pushed out of the cell, they collect another substance and moves it into the cell.
An primary active transport is direct pumping of a substance against its gradient whilst using ATP.
Hopefully this helps