"Home Button in final cut

I have a very silly question - the anwswer is probably right in front on my face! When in Final cut on my MacPro Laptop - when do I hit fro "media start" and "media end?" O n regular keyboard - it's "home" and "end." In the drop down menus at the top - the quick kys are refered to as these thin arrows...not sure whaere that is on my laptop key board...anybody know? thanks!