amino acid - (Dec/13/2005 )

threonine (amino acid) : ACU, ACC, ACA, ACG implies that point mutations at the third postion will have no effect right? or is it insertion mutation?
can anyone confirm this? thank you :]

That depends on witch mutation occurs. Point mutation or subsitution on the third position result in no aa change. If its a insertion you most possible get a aa change.

If it is a point mutation (swapping one base for another), it is a silent or null mutation -- it does not result in a change in protein sequence.

An insertional mutation implies that a base was inserted that wasn't there before. This will cause a frameshift and screw the synthesis of this protein up badly (unless there is a corresponding single-base deletion that occurrs someplace very nearby that puts the translation frame back in order).