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.
Typically, it is recommended that you ask for an RSVP date at least three weeks before your wedding, as long as you have sent them on time. At a minimum, send out your wedding invitations six weeks in advance and set an RSVP date of two weeks before the wedding. If you get into a situation where some guests have not gotten back to you, feel free to call them.