Composition of Biological Molecules

What are biological molecules composed of?


  • Select one of the following biological molecules
  • Open  3DChem
    • Note:  if 3DChem is not working, use CheMagic.  In the search window (where it it says "Enter Jmol script or load commands here."), type  load [compound name]. For example, load [Adenine].  Make sure to include brackets.  Alternatively, you may choose a molecule from this index.
  • View the molecule as a "Ball" or "ball & stick model. Make sure that hydrogens are visible.  
  • View the molecule in 3D and rotate in space.
  • Turn on the labels to identify the atoms in each molecule
    • Note:  if unable to see labels, follow this color code:  Carbon (black or gray), hydrogen (white), nitrogen (blue), sulfur (yellow), oxygen (red), phosphorus (orange)
  • Record the number of each atom for the molecule in question in the form.  
  • Examine the raw data for the entire class. 
  • Examine the summary data for the entire class. 


  • What can you conclude about the composition of biological molecules?
  • Are there significant differences between the composition of the various classes of biological molecules?  If so, please explain