IIRC - yes.. Raid 5 will give you 1 drive redundancy. so it will boot and work fine.
but you need replace it as a second failure will mess you up.http://en.wikipedia.org/wiki/RAID
and ofc.. if its all "Hot swap".. make sure you replace the correct one... don't do what an engineer did for us and remove the wrong one.. which then killed the array!!!