Question

What determines the function of an organic molecule?

Answer 1

I am answering this question with respect to organic molecules in proteins. In case of proteins, the sequence of proteins (order) greatly affects the function of protein.For example, in enzymes the binding site or catalytic site has a catalytic residues (organic molecules = amino acids) at specific positions. And these amino acids together catalyzes the reaction. Like Serine, Histidine and Aspartic in chymotripsin together catalyzes the hydrolysis of protein and they have specific order (i.e serine 195, histidine 57 and aspartic acid 102. So, order is very important in functionality of protein.

Secondly, the shape is very important. Like, in above example the -OH group of Asp protonates the carbonyl groups in substrate, the -OH group of Ser acts as a nucleophile and the -NH group of His acts as a base by abstracting the protons during the reaction. So, it is the shape of these amino acids which are helping in functioning the enzyme.

So, the correct answer is Order and Shape.