Flipbook animation- Editing textures independently

I’m trying to make this really cool animation effect by combining multiple images of a flower ( Growing at different stages) and I’ve done some research on achieving this and so far it’s been great…so basically I put this animation on a plane and it displayed the crop sprouting and blossoming into a flower.

But I wanted to combine this with particle effects…and get an aesthetically pleasing animation…

So my question is :

How do I make (or edit) the 3rd texture in my animation (in total I have 10 pictures/textures) independently of the others such that when the animation is playing, and once it reached the 3rd picture ( I want the 3rd texture to glow- In other words I want to use emissive on this texture without using it on the whole animation)

It’s pretty hard for me to explain this as I just got started with particles and animations…but if you get the point or a better technique please help me out .