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Table Of Contents |
The programme starts by summarising TV.3 "The Structure of Lysozyme" with a sequence
in which various rotating models of the lysozyme molecule are superimposed to highlight
some distinctive features, ending with the "cleft" which is involved in the action.
Professor David Phillips of Oxford University explains that to describe the action
of lysozyme, it is relevant to consider why the chain molecule takes up its particular
globular shape. The model used in TV3, of the chain of 129 amino-acid residues, changes
colour to distinguish between the hydrophilic and hydrophobic side-chains. A computer
animated film builds up the molecule to show that hydrophilic side-chains remain on
the surface, whereas hydrophobic side-chains are folded into the interior. This is
illustrated again on a "hydrophilic/hydrophobic" model of the molecule. The action
of lysozyme on bacterial cell walls is described using a microscopy film, three video
animation sequences describing the polysaccharide structure of a cell wall, a model
of the active site attached to a six-ring segment of a polysaccharide, two separate
models of this hexasaccharide, an animated film of the action and, finally, the earlier
"hydrophilic/hydrophobic" model of lysozyme. The programme ends with various superimpositions
of the rotating globular-shaped models. |