Describe one similarity in the interaction between receptor: hormone , antibody: antigen, enzyme: substrate ?

All mentioned complexes (receptor-hormone, antibody-antigen, enzyme-substate) are involved in a molecular recognition.The molecular recognition involves non-covalent  interaction between molecules. To form complex, molecules must be complementary in shape and charges, and usually, they are compared to key and lock. This way, the selectivity and specificity of recognition between molecules are assured.

This type of galaxy is an approximately ellipsoidal shape and a smooth, nearly featureless image. they are the largest single star systems, in the universe and are built by the collisions of many smaller galaxies.