Final answer:
Lipid-based signaling molecules, such as steroid hormones, are synthesized in endocrine glands and can diffuse across the plasma membrane due to their lipophilic nature. They activate intracellular receptors affecting gene transcription or bind to cell-surface receptors to initiate a signaling cascade. The inhibition of enzymes like adenylyl cyclase, which produces cAMP as a second messenger, can disrupt these signaling pathways.
Step-by-step explanation:
Lipid-soluble ligands, such as steroid hormones, are synthesized in the endocrine glands. They are released into the bloodstream and can diffuse across the plasma membrane of target cells due to their lipophilic nature. These molecules often function as hormones that bind to intracellular receptors, leading to changes in gene transcription, or bind to cell-surface receptors, initiating a signaling cascade involving second messengers like cAMP. When a ligand binds to a receptor on a cell's surface, it may activate a G-protein, which in turn can activate or inhibit enzymes like adenylyl cyclase. This enzyme is responsible for the synthesis of cAMP from ATP, which acts as a second messenger in signaling pathways. The activation (or inhibition) of particular pathways can lead to various cellular responses, ranging from altered membrane permeability to the production of enzymes and changes in metabolic activities. It's important to note that an inhibitor of adenylyl cyclase will block the synthesis of cAMP, which is a crucial step in certain signaling pathways initiated by G-proteins. Therefore, if adenylyl cyclase is inhibited, there would be an impact on the cell's ability to generate a response to certain hormones or signaling molecules.