Question

What is so important about atomic structure?

Answer 1

Well, atomic structure - determines the properties and behavior of the element - its chemistry.
You can derive a lot of knowledge when you know something about its structure.

Answer 2

theres two aspects of this. Configuration and conformation. Look up glucose and you will see (d) and (l)- glucose. This is configuration and the reason configuration is important is so your body can distinguish between the two sugars(one your body likes the other it can break down) and secondly conformation has to do a lot of the time with sterics. If your in a room with 50 people and there are 5 other rooms with no one in them , people will realize this a disperse. Same with molecules, if a reaction happens that creates a lot of strain on the product, it will break and try to reform in a better way. Very important in everything, Those two aspects are why you can eat food and taste it and digest it.