The evolution of signaling molecules has made it possible for cells of multicellular organisms, such as humans, to communicate with one another in simple and complex ways. Signaling molecules may be used to transmit information between cells (extracellular or intercellular signaling), or they may be involved in signaling cascades inside cells (cytoplasmic or intracellular signaling). Test your basic knowledge of signaling molecules by taking this simple quiz.
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(1) In the biosynthetic pathway of catecholamines, the enzyme L-aromatic amino acid decarboxylase catalyzes the following reaction:
(2) In the biosynthetic pathway of catecholamines, the enzyme dopamine β-hydroxylase catalyzes the following reaction:
(3) In the biosynthetic pathway of catecholamines, the enzyme phenylalanine N-methyltransferase (PNMT) catalyzes the following reaction:
(4) Which of the following hormones exert their actions by binding to plasma membrane receptors in target cells?
(5) Which of the following hormones exert their actions by binding to intracellular receptors in target cells?
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Posted: Monday, February 1, 2016
Last updated: Tuesday, March 11, 2025
Last updated: Tuesday, March 11, 2025
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