Much of this movement is to regulate the contents of the cell. This includes bringing material into the cell from the extracellular environment or the plasma membrane (endocytosis) or releasing material made within the the cell to the outside (exocytosis).
It really is an easy project...it just takes a little time. All and all, it took me about 6-8 total hours to make 4 bouquets, 10 bouts (my mom made those though) and about 15 centerpieces. I made two bouquets the day before our wedding and the other two the day of the wedding.
Get organized about a month before your desired invitation send-out date. This should be six to eight weeks before the wedding, allowing your guests adequate time to respond and ensuring that you will get a reliable head count a week or two before the event.