Arrange the events for the hydrolysis of amide bonds by chymotrypsin in their correct order. 1) attack by ser 195 to give a tetrahedral intermediate 2) enzyme returns to initial state 3) protonation by his 57 and then cleavage of the c-n bond release the c-terminal fragment 4) protonation by his 57 and then cleavage of the c-o bond release the n-terminal fragment 5) attack by water, leading to formation of a tetrahedral intermediate 6) binding of substrate to properly position the scissile bond for cleavage