Moving gameobject with animation according to my script

I am developing a game with Unity3D with an horizontal list of elements which you can move with arrows. Here you can see an example:

I have created animations in order to modify the alpha value of the elements and to move them according to my script:

 void Update () {
     if (managePositionInUpdate) {
         transform.position = Camera.main.ScreenToWorldPoint (new Vector3 (Screen.width * positionX, Screen.height * positionY, 10));
     }
 }

In my animation, the alpha value of the centered element is initially 1 and after the animation the alpha value is 0.5, this works correctly; however, in this animation I have also put positionX of my script initially with a value A, and after the animation with a value B, and this doesn't work correctly.

I have tested the code and it works correctly without animation, but I can't get it works according to my animation. What can I do? I have read about apply root motion but It also doesn't work for me.