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.
Ideally, wedding invitations should be sent 8 weeks in advance. You should ask for people to RSVP no later than 3 weeks before your wedding. Way too early. I wouldn't sent them out till 6-8 weeks before the wedding. I'd send them out in about Mid-May. Only because people are going out of town during the summer.