Many scientists use chemical inhibitors to interfere with normal signaling pathways within eukaryotic cells. if such inhibitors are large, nonpolar molecules, what is the likely method of action of these chemical inhibitors?
a) these chemical inhibitors likely function in the cytoplasm, where they interfere with the termination of signaling, so eukaryotic cells can't process new signals.
b) these chemical inhibitors likely bind to receptors on the cell surface and interfere with receptor activation or signal-receptor binding.
c) these chemical inhibitors likely enter eukaryotic cells and interfere with components of the signal transduction pathway.
d) these chemical inhibitors likely enter the nucleus and prevent the transcription of the pathway of interest's target genes.

Chemical inhibitors likely bind to receptors and interfere with receptor activation or signal-receptor binding.

Explanation:

The signaling pathway requires the generation of a signal, its reception by target cells, signal transduction and cellular response. According to the given information, the inhibitors are the large and non-polar molecules. The cell membranes do not allow free passage of large molecules. Therefore, these inhibitors are most likely to interfere with signal reception by target cells.

For the purpose, the inhibitors may bind to the receptors present on the surface of target cells and thereby, not allowing the binding of the signaling molecule to the receptors and the activation of the receptors. Unless the signaling molecule binds to its receptors present on the surface of target cells, receptors remain inactive and there is no signal transduction.

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

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