Physiological modulators effectors, other

Covalent modHication of enzymes, enzyme modulation, enzyme interconversion Oligomeric (i.e. multichain) enzymes may exist in two or more forms, which are interconvertible by enzyme-catalysed covalent modifications, and which differ in their catalytic properties, e.g. activity, substrate affinity and dependence on effectors. Usually the difference in activity is such that one form is active and the other inactive. The activities of the conversion enzymes are in turn regulated by other enzymes, metabolites and/ or effectors. Covalent modifications are therefore important in physiological regulation, in addition to Allostery (see). Whereas allostery provides fine adjustment of metablic rates, C provides an on/off switching of cellular functions, which is very sensitive to environmental influences. 

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