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    i know this occurs when insulin is secreted but how bout glucagon?
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    Interesting question!

    I think the big big misconception you might have is that I think you have insulin and glucagon the wrong way around.
    Glucagon does activate adenylyl cyclase, but insulin doesn't (it's mechanism of action is through a receptor tyrosine kinase).

    If you'd like me to go into a bit more detail on it:

    1. Glucagon and insulin are both peptide hormones (and since they are relatively polar they cannot diffuse through the membrane like steroid hormones so instead bind to receptors on the outer membrane of cells).
    2. The receptor Glucagon specifically binds to is a G-protein coupled receptor, and insulin to a receptor tyrosine kinase.
    3. Just to talk about adenylyl cyclase, the binding of glucagon causes the displacement of GDP with GTP on the alpha subunit of the G-protein coupled receptor, and the alpha subunit dissociates and migrates over to adenylyl cyclase, hence activating it!

    My usual disclaimer of 'I'm just an A level student so take my knowledge with a pinch of salt!'

    Hope I helped a tiny bit!

    Edit: Whoops! I forgot to address the last part of your question which is about liver cells - Yes, its target cells are predominantly those in the liver (also known as hepatocytes)
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    (Original post by Spectral)
    Interesting question!

    I think the big big misconception you might have is that I think you have insulin and glucagon the wrong way around.
    Glucagon does activate adenylyl cyclase, but insulin doesn't (it's mechanism of action is through a receptor tyrosine kinase).

    If you'd like me to go into a bit more detail on it:

    1. Glucagon and insulin are both peptide hormones (and since they are relatively polar they cannot diffuse through the membrane like steroid hormones so instead bind to receptors on the outer membrane of cells).
    2. The receptor Glucagon specifically binds to is a G-protein coupled receptor, and insuline to a receptor tyrosine kinase.
    3. Just to talk about adenylyl cyclase, the binding of glucagon causes the displacement of GDP with GTP on the alpha subunit of the G-protein coupled receptor, and the alpha subunit dissociates and migrates over to adenylyl cyclase, hence activating it!

    My usual disclaimer of 'I'm just an A level student so take my knowledge with a pinch of salt!'

    Hope I helped a tiny bit!

    Edit: Whoops! I forgot to address the last part of your question which is about liver cells - Yes, its target cells are predominantly those in the liver (also known as hepatocytes)
    I've got my textbook right here and it does say insulin activates adenyl cyclase in its target cells which are hepatocytes and muscle cell. Although my textbook is old and OCR are really stupid!
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    (Original post by Shiv is Light)
    I've got my textbook right here and it does say insulin activates adenyl cyclase in its target cells which are hepatocytes and muscle cell. Although my textbook is old and OCR are really stupid!
    That's definitely wrong. Glucagon binding to the glucagon receptor, a G-protein-coupled receptor, activates adenylyl cyclase, subsequently increasing the intracellular cAMP concentration. Insulin, on the other hand, binds to the insulin receptor, an enzyme-coupled receptor that is coupled to the enzyme tyrosine kinase, the activation of which leads to various signal transduction pathways in different tissues.
 
 
 
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