Question

Predict what would happen if you injected a water-soluble hormone into the cytosol of a target cell.

Short answer

When the water-soluble hormone is injected into the cytosol of the target cell, the receptor for the water-soluble hormone is present on the surface of the target cell and thus, does not provoke a cellular response.

Step-by-step solution

Water-soluble hormone

A water-soluble hormone is a lipophobic hormone that cannot diffuse through the cell membrane and bind to their respective receptors expressed on the surface of the target cell membrane.

For example, epinephrine is a water-soluble hormone secreted by the adrenal gland located on the top of the kidneys.

Cellular response by a water-soluble hormone

In case water-soluble hormone binds to a receptor present on a cell-surface protein, it initiates a cellular response caused by the activation of an enzyme. Cell-surface receptors can lead to protein movements into the nucleus from the cytoplasm and regulate specific gene transcription.

No cellular response is triggered when a water-soluble hormone is injected into the cells

When a water-soluble hormone such as adrenaline is injected into the cytosol of the target cell, the hormone cannot bind to its receptor; this is because the receptors for water-soluble hormones facing the extracellular space are found on the cell surface.

As a result, no cellular response would be triggered.