Building an Organic Molecule

By Kate Fraser on Dec 29, 2013

Purpose:

By providing students who are blind or visually impaired with a three dimensional model of a sugar molecule, this activity demonstrates the shape of a molecule that everyone hears about but never sees.  Glucose is a simple sugar created during photosynthesis in plants. This activity illustrates the bonding of carbon and other atoms to form this important molecule. Building and examining this model provides an introduction to the world of chemicals found in all living things

Background information:

Organic molecules are the compounds that are the building blocks of all living things.  These macromolecules (very large molecules) contain carbon, hydrogen, and oxygen, and in some cases, a few other elements. Carbohydrates, sugars and starches, represent one type of organic molecule. The smallest carbohydrates are simple sugars.  Glucose, blood sugar is an example of a simple sugar. During this activity, students can review, or learn about for the first time, the type of bonding, covalent, that holds the carbons together in this molecule.  Students can later compare the shape of this molecule to the shape of molecular models of fats, proteins, and nucleic acids.  In the world of organic chemistry the shape of a molecule is related to how it functions in living organisms.

This activity uses a commercially available molecule building kit designed for use in science classes.  The models are color coded, and can be readily identified by color by many students with a visual impairment.  More significantly, the models can also be readily identified by touch.  The elements represented are oxygen, carbon, and hydrogen.  Hydrogen is smaller in size than oxygen or carbon, and is represented by a smaller white plastic model, with one hole or bonding spot, representing hydrogen's sole electron.  Oxygen is represented by a larger, red plastic model with two holes representing oxygen's ability to accept to additional electrons. Carbon is black and has 4 holes where it can accept four additional electrons from another atom. Short and long gray plastic links represent the bonds between atoms.

Preparation:

This activity needs very little preparation.  Students benefit from learning to tactually and/or visually identify the models of the component elements before beginning to assemble the molecule.  Some students may require the teacher to set up the tray with the atoms and links organized in separate containers.  These models are science teaching aids that with very little adaptation work well for the visually impaired. Some science classrooms may already have these models available.

Materials

  • Molymod® molecular model kit
  • Tray (APH tray with dividers, or a cafeteria tray with small containers)
  • Small containers for organizing materials
  • Tactile and/or large print model of the glucose molecule (structural formula)
  • Tactile and/or large print written version of the molecule (empirical formula)

Procedure

  1. Examine the structural and empirical formulas of the molecule, C6H12O6.
  2. Locate and identify the various components that will comprise the completed model. 
  3. Assemble the model, starting by building the various components that come together to make glucose. 
  4. Following the atomic combinations indicated in the structural diagram, first build a chain of 5 carbons.
  5. Add oxygen to the chain of carbons, using the longer bonds, and then form a ring. 
  6. Next, build one component representing CH2OH.  This attaches to the carbon ring.  
  7. Then build 4 hydroxyl ions (-OH). One of these hydroxyls will attach to the carbons that have 2 bonding spots available.
  8. Add hydrogen atoms to the remaining bonding spots.
  9. Compare the 3 dimensional shape to the tactile/ large print diagrams
  10. Build more complex carbohydrates by joining together the sugar molecules.

Resources:

www.molymod.com

Molecular model kits are also available from Flinn Scientific, Inc.  www.flinnsci.com

 

molecule collage

 

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