That’s Right! This Week’s Molecule will be Glucose!
Here’s some information about Glucose:
Glucose is a very important molecule, it is simply how energy is stored and transported in biological systems. Glucose transports in the blood of animals and humans as what we know as blood sugar and it is being made during the process of photosynthesis in plants. Whether humans, animals or plants glucose is our real source of energy!
Glucose is a monosaccharide with the chemical formula C6H12O6, it contains five hydroxyl groups, a carbonyl group and an aldehyde group. These are all displayed in a specific way along its six-carbon backbone. The glucose molecule can be displayed in an open chain form and also in a cyclic form. The cyclic form of glucose is usually seen when in a solution.
When in solution it exists in equilibrium displaying several cyclic isomers with each forming two main types of anomers: Alpha and Beta configuration. See below a picture displaying both configurations of the glucose molecule:
Alpha Vs Beta Glucose
The real difference between the alpha and beta glucose is simply the position of one of the hydroxyl (-OH) groups in the cyclic ring. The carbon (#1) which is to the right of the oxygen atom in the cyclic ring is called an anomeric carbon, hence forming the anomer. If the hydroxyl group attached is positioned below the ring, then the molecule is an alpha glucose; however if the hydroxyl group attached is positioned above the ring, then the molecule is a beta glucose.
Glucose molecule can interchange between open chain form and cyclic form, they are also able to convert between an alpha glucose and a beta glucose. The type of anomer is dependent on the use of the glucose molecule and the position of its binding sites.
Let’s Get Building!
Using your Student Molecular Set from Duluth Labs, let’s create glucose. You’ll need:
- 6 Carbon Atoms
- 6 Oxygen Atoms
- 12 Hydrogens
- 12 Small connectors (compact short bonds for hydrogen)
- 12 Medium connectors (single covalent bonds)
- Molecular Tool (for Disassembly)
Put aside all the atoms and connectors needed.
We will be building this molecule starting with the oxygen in the “6-membered ring”. We will be adding the carbon atoms in a clockwise position.
1. Using a medium connector attach a carbon atom to the right of the oxygen atom.
2. Using other medium connectors, add four more carbon atoms to each other forming the backbone ring, this should connect back to the oxygen atom.
Congrats! You’ve successfully built the backbone needed to build glucose.
Note: Since you now have your backbone structure, we will start off by first building an alpha glucose, in this case the hydroxyl group (-OH) attached to carbon #1 is positioned below the ring.
3. Starting with our #1 carbon (carbon to the right of the oxygen atom), in the hole facing you, use a short connector to attach a hydrogen atom. This is a representation that the hydrogen atom is “above” the ring.
4. Creating a Hydroxyl (-OH) Group: On the same carbon #1 atom, in the hole facing downwards use a medium connector to attach an oxygen atom and then a short connector to attach the hydrogen atom to the oxygen atom thus forming your hydroxyl (-OH) group.
Note: This hydroxyl group should be pointing away from you and is an indication that the group is positioned below the ring.
Now that you have successfully built the alpha anomer, it’s time to build out the remainder of the glucose molecule!
5. At carbon #2, in the hole facing you, use a short connector and attach a hydrogen atom. Then in the hole behind, use a medium and a short connector as instructed above to attach your hydroxyl group.
Note: Once again this will indicate that the hydrogen is positioned above the ring while the hydroxyl group is below the ring.
6. At carbon #3 using a medium connector and a short connector attach a hydroxyl group in the hole facing you. Then, use a short connector to attach a hydrogen in the hole below.
7. At carbon #4 using a short connector attach a hydrogen atom in the hole facing you. Then use a medium connector and a short connector respectively to attach a hydroxyl group in the remaining hole.
8. At carbon #5 using a medium connector attach the final carbon atom (Carbon #6) in the hole facing upwards.
9. At carbon #6 use a medium connector and a short connector to attach the final hydroxyl group.
10. Using the remaining small connectors attach hydrogen atoms in the open holes on the molecule.