Being able to draw glucose is an important step to understanding important chemical reactions inside of living cells such as Glycolysis or Gluconeogenesis. Glucose is also an important source of energy for cells in many different organisms that range from bacteria to mammals. Being able to easily draw glucose is a fundamental step to learning higher level chemistry or biology.
The empirical formula of glucose is C6H12O6. This means every time you draw glucose there should be:
- 6 Carbon atoms
- 6 Oxygen atoms
- 12 hydrogen atoms.
Since carbon is the backbone of organic molecules I suggest counting Carbon atoms first, then oxygen, and placing hydrogen in any free locations. If you know how many Carbon and Oxygen atoms are in glucose then remembering where the 12 hydrogen atoms go is like filling in the free space. The simple rules below will make drawing the structure of glucose much easier. You can review the periodic table if you want to know where I got the number of bonds from.
The Open Chain Structure
An easy way to draw the open chain structure of glucose is to follow these 3 steps:
You should only need to remember which side of the chain the oxygen atoms are. If you count the number of bonds on each carbon, and count the number of bonds of each oxygen atom, you can fill in the rest of the structure with hydrogen atoms.
The Cyclic (ring) Structure
When drawing the ring structure of glucose or any other molecule, most of the carbons atoms are represented by a bent line. Just for technical purposes I am showing the alpha-D-glucose molecule below. This is the form of glucose used to make starches such as amylose and amylopectin that are easily digestible. This is the form of glucose that should be studied in most biology courses.
[gn_note color=”#21ab2f”]The OH groups always bonds to the ring from the oxygen atom. -OH and HO- are correct but -HO is not. Remember the bonding rules above[/gn_note]. [gn_divider top=”0″]