Subject: active and passive transport of molecules

What properties of organic molecules (protein, carbohydrate, lipid, nucleic acid, 
phospholipids, atp, etc) determines the type of active or passive transport of 
molecules into or out of the cell?  The question that came up to me was to be 
able to identify different structures of molecules that are assocciated with the 
movement of molecules through the cell membrane, such as; nucleic acid, ATP, 
amino acids, starch etc. Also I am required to state how protein, oxygen, water, 
amino acids and steroid hormones cross the cell membrane to enter the cell. I 
want to know how or what determines the method of transport, of these organic 
molecules?

Re: active and passive transport of molecules