ABSTRACT
A carbon atom with four different substituents can exist in two different forms; enzymes have a high degree of specificity for particular structures; and whether a carbon atom has one, two, or three carbon atoms connected to it will dictate the type of reactions that it can, and cannot, engage in. What unifies these different phenomena? The three-dimensional structure, that is to say, that molecules are not flat, but they adopt different shapes depending on the number.
