| Popis: |
We have found it an effective way of teaching symmetry in the context of stereoselectivity, to use common everyday objects with the same point groups as the substrates involved. This has helped students to distinguish between those symmetry elements which allow for stereospecificity and those which preclude it. Two symmetry elements, the simple rotation axis and the mirror plane, are needed to explain the equivalence (or its absence) between atoms or groups in the substrate while interacting with the chiral enzyme. We have used familiar objects such as blackboard erasers, scissors and purses to illustrate the point group symmetry of substrates such as ethanol, citrate, succinate and fumarate and the interaction between the EcoRI restriction enzyme and the EcoRI-DNA palindromic complex. |
