Question

How are metabolic networks regulated? Which of the following statements IS NOT TRUE? A) hormones signal when a certain pathway is to be inactivated because the end-product accumulates at high levels. B) regulation of enzymatic activity is predominantly focused on the availability (concentration) of substrates. C) metabolic networks are typically regultaed by the accumulations of end-point metabolites that inhibit pathway specifying enzymes. D) the end metabolite (final product of a specific pathway) is the inhibitor of the first enzyme pathway-specific converting enzyme.

Answer 1

The end metabolite (final product of a specific pathway) is the inhibitor of the first enzyme pathway-specific converting enzyme is not a true statement - Only when the end metabolite is accumulated or has been produced in high quantities, inhibition of the enzyme will be efficient for the pathway and metabolism. The regulation of metabolism takes place through feedback inhibition and also is regulated by the availability of substrates for the enzymes to bind.