Question

Describe how molecular models may be used to represent a range of molecules of different shapes.

Answer 1

A molecular model is a model considered as a physical model, that is used to represent structures of molecules and their processes. The molecular model will primarily refer to systems containing more than one atom and where a nuclear structure is neglected. For understanding all the aspects of molecular structure, a comprehension of the three-dimensional form of the molecular structures is required. The presentation of a chemical formula in the two-dimensional form of the page of a book can reveal the presence of potentially reacting groups but it cannot indicate whether they will be organized in the correct spatial manner to interact productivity. Therefore,various molecularmodels are used.

• Space-filling models are excellent for showing the way in which the atoms of a macromolecule are closely packed together and for demonstrating the shapes of surfaces which interact together such as the active site cleft of an enzyme.
• The underlying molecular architecture, particularly of structures having tertiary or quaternary levels of the organization, can be shown much more readily by means of skeletal or baH-and-spoke models.
• The very simple 'poppet-bead' type of model can give a clear illustration of the general shape of the backbone of a biopolymer and the general disposition of the various types of chemical groups along with it.