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How do the control mechanisms in glycogen metabolism lead to amplification of response to a stimulus?

User Mondayrris
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1 Answer

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Glycogen

Step-by-step explanation:

  • This is based on the fact that the response to hormones generates a signaling cascade that eventuates in the activation or inhibition of enzymes involved in glycogen metabolism
  • The benefit of a multi-step cascade is that it amplifies the signal which means that response can be fast and significant
  • High level of secondary messenger, cyclic adenosine monophosphate (cAMP) activates a protein called protein kinase A (pKA) which phosphorylates phosphorylase kinase (pK) and activates it
  • On the other hand at the same time pKA phosphorylates glycogen synthase and inactivate it
  • pK becomes active that phosphorylates glycogen phosphorylase and makes it active, glycogen phosphorylase catalyse breakdown of glycogen (in liver and muscle cells)
  • Activated protein kinase A enters in nucleus and phosphorylate a transcriptional activator called cyclic AMP response element binding protein (CREB)
  • Phosphorylated CREB becomes active and binds to a DNA element called cyclic AMP response element (CRE) and induce transcription of various genes which involved in glucose metabolism
User Jonas Eicher
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