Manufacturing of Bio Molecules
There are literally millions of biomolecules.  Some of them we know the structures and chemical properties of others we know nothing about.   I'm going to focus on sugars.  It would be too broad a question probably even to list all biomolecules, much less describe how their chemical synthesis would be performed. 

The good news is that industrial manufacturing of biomolecules is done for thousands of compounds and even available.  Certainly chemical synthesis of sugars is possible and even available but is very expensive and often produces side products compared to fermentation processes or extraction from plants say.  

Sugars, for instance glucose are very similar, but if you look at this structure you will see that the four OH (alcohol) groups could point up or down.  Any manufacture of glucose would have to get each one of these bonds exactly right.  This is D-glucose, which is commonly available as extracted with water from sugar beets and sugar cane.  I can buy 10 pounds of it at the store for less than $10.  



Compare with L-glucose, which is synthesized by a chemist.  Its available (though not really recommended for human consumption because its got impurities and doesn't necessarily pass FDA definitions of purity to be a food) at the cost of $87 per gram. 

So the answer is probably best put like this: who would pay \$87,000 for a bag of sugar when they could pay $10?  Cases where one would have to pay a company to produce a biomolecule, its going to cost...