THE CELL
CELL COMMUNICATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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There are too many proteins in the signal transduction pathway.
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More than one answer is correct.
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The concentration of a neurotransmitter is too low.
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The number of receptors in the plasma membrane is too low.
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The concentration of a hormone is too high.
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Detailed explanation-1: -Elevated levels of the hormone insulin in the blood trigger downregulation of the associated receptors. When insulin binds to its receptors on the surface of a cell, the hormone receptor complex undergoes endocytosis and is subsequently attacked by intracellular lysosomal enzymes.
Detailed explanation-2: -Under which of the following situations would receptor down-regulation most likely occur? The concentration of a hormone is too high.
Detailed explanation-3: -Downregulation: An decrease in the number of receptors on the surface of target cells, making the cells less sensitive to a hormone or another agent. For example, insulin receptors may be downregulated in type 2 diabetes.
Detailed explanation-4: -Downregulation • Downregulation specifically refers to a reduction in the total number of receptors available to be stimulated due to prolonged receptor activation (e.g. by chronic treatment with a pharmacological agonist drug or prolonged inhibition of metabolism of a neurotransmitter).